diff --git a/google-cloud-clients/google-cloud-automl/src/main/java/com/google/cloud/automl/v1beta1/stub/AutoMlStubSettings.java b/google-cloud-clients/google-cloud-automl/src/main/java/com/google/cloud/automl/v1beta1/stub/AutoMlStubSettings.java
index 066c763e6f30..edf8b4186f9b 100644
--- a/google-cloud-clients/google-cloud-automl/src/main/java/com/google/cloud/automl/v1beta1/stub/AutoMlStubSettings.java
+++ b/google-cloud-clients/google-cloud-automl/src/main/java/com/google/cloud/automl/v1beta1/stub/AutoMlStubSettings.java
@@ -371,7 +371,9 @@ public String extractNextToken(ListDatasetsResponse payload) {
 
             @Override
             public Iterable<Dataset> extractResources(ListDatasetsResponse payload) {
-              return payload.getDatasetsList();
+              return payload.getDatasetsList() != null
+                  ? payload.getDatasetsList()
+                  : ImmutableList.<Dataset>of();
             }
           };
 
@@ -405,7 +407,9 @@ public String extractNextToken(ListModelsResponse payload) {
 
             @Override
             public Iterable<Model> extractResources(ListModelsResponse payload) {
-              return payload.getModelList();
+              return payload.getModelList() != null
+                  ? payload.getModelList()
+                  : ImmutableList.<Model>of();
             }
           };
 
@@ -444,7 +448,9 @@ public String extractNextToken(ListModelEvaluationsResponse payload) {
             @Override
             public Iterable<ModelEvaluation> extractResources(
                 ListModelEvaluationsResponse payload) {
-              return payload.getModelEvaluationList();
+              return payload.getModelEvaluationList() != null
+                  ? payload.getModelEvaluationList()
+                  : ImmutableList.<ModelEvaluation>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-bigquerydatatransfer/src/main/java/com/google/cloud/bigquery/datatransfer/v1/stub/DataTransferServiceStubSettings.java b/google-cloud-clients/google-cloud-bigquerydatatransfer/src/main/java/com/google/cloud/bigquery/datatransfer/v1/stub/DataTransferServiceStubSettings.java
index b3e2881f9f68..8ead53dbbf49 100644
--- a/google-cloud-clients/google-cloud-bigquerydatatransfer/src/main/java/com/google/cloud/bigquery/datatransfer/v1/stub/DataTransferServiceStubSettings.java
+++ b/google-cloud-clients/google-cloud-bigquerydatatransfer/src/main/java/com/google/cloud/bigquery/datatransfer/v1/stub/DataTransferServiceStubSettings.java
@@ -329,7 +329,9 @@ public String extractNextToken(ListDataSourcesResponse payload) {
 
             @Override
             public Iterable<DataSource> extractResources(ListDataSourcesResponse payload) {
-              return payload.getDataSourcesList();
+              return payload.getDataSourcesList() != null
+                  ? payload.getDataSourcesList()
+                  : ImmutableList.<DataSource>of();
             }
           };
 
@@ -367,7 +369,9 @@ public String extractNextToken(ListTransferConfigsResponse payload) {
 
             @Override
             public Iterable<TransferConfig> extractResources(ListTransferConfigsResponse payload) {
-              return payload.getTransferConfigsList();
+              return payload.getTransferConfigsList() != null
+                  ? payload.getTransferConfigsList()
+                  : ImmutableList.<TransferConfig>of();
             }
           };
 
@@ -405,7 +409,9 @@ public String extractNextToken(ListTransferRunsResponse payload) {
 
             @Override
             public Iterable<TransferRun> extractResources(ListTransferRunsResponse payload) {
-              return payload.getTransferRunsList();
+              return payload.getTransferRunsList() != null
+                  ? payload.getTransferRunsList()
+                  : ImmutableList.<TransferRun>of();
             }
           };
 
@@ -443,7 +449,9 @@ public String extractNextToken(ListTransferLogsResponse payload) {
 
             @Override
             public Iterable<TransferMessage> extractResources(ListTransferLogsResponse payload) {
-              return payload.getTransferMessagesList();
+              return payload.getTransferMessagesList() != null
+                  ? payload.getTransferMessagesList()
+                  : ImmutableList.<TransferMessage>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-bigtable-admin/src/main/java/com/google/cloud/bigtable/admin/v2/stub/BigtableInstanceAdminStubSettings.java b/google-cloud-clients/google-cloud-bigtable-admin/src/main/java/com/google/cloud/bigtable/admin/v2/stub/BigtableInstanceAdminStubSettings.java
index 652a428be167..2f591436e728 100644
--- a/google-cloud-clients/google-cloud-bigtable-admin/src/main/java/com/google/cloud/bigtable/admin/v2/stub/BigtableInstanceAdminStubSettings.java
+++ b/google-cloud-clients/google-cloud-bigtable-admin/src/main/java/com/google/cloud/bigtable/admin/v2/stub/BigtableInstanceAdminStubSettings.java
@@ -421,7 +421,9 @@ public String extractNextToken(ListAppProfilesResponse payload) {
 
             @Override
             public Iterable<AppProfile> extractResources(ListAppProfilesResponse payload) {
-              return payload.getAppProfilesList();
+              return payload.getAppProfilesList() != null
+                  ? payload.getAppProfilesList()
+                  : ImmutableList.<AppProfile>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-bigtable-admin/src/main/java/com/google/cloud/bigtable/admin/v2/stub/BigtableTableAdminStubSettings.java b/google-cloud-clients/google-cloud-bigtable-admin/src/main/java/com/google/cloud/bigtable/admin/v2/stub/BigtableTableAdminStubSettings.java
index ad6034d6c922..4ee935113e58 100644
--- a/google-cloud-clients/google-cloud-bigtable-admin/src/main/java/com/google/cloud/bigtable/admin/v2/stub/BigtableTableAdminStubSettings.java
+++ b/google-cloud-clients/google-cloud-bigtable-admin/src/main/java/com/google/cloud/bigtable/admin/v2/stub/BigtableTableAdminStubSettings.java
@@ -347,7 +347,9 @@ public String extractNextToken(ListTablesResponse payload) {
 
             @Override
             public Iterable<Table> extractResources(ListTablesResponse payload) {
-              return payload.getTablesList();
+              return payload.getTablesList() != null
+                  ? payload.getTablesList()
+                  : ImmutableList.<Table>of();
             }
           };
 
@@ -381,7 +383,9 @@ public String extractNextToken(ListSnapshotsResponse payload) {
 
             @Override
             public Iterable<Snapshot> extractResources(ListSnapshotsResponse payload) {
-              return payload.getSnapshotsList();
+              return payload.getSnapshotsList() != null
+                  ? payload.getSnapshotsList()
+                  : ImmutableList.<Snapshot>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AcceleratorTypeStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AcceleratorTypeStubSettings.java
index d29f00a0a695..099d5983abd9 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AcceleratorTypeStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AcceleratorTypeStubSettings.java
@@ -250,7 +250,9 @@ public String extractNextToken(AcceleratorTypeAggregatedList payload) {
             @Override
             public Iterable<AcceleratorTypesScopedList> extractResources(
                 AcceleratorTypeAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<AcceleratorTypesScopedList>of();
             }
           };
 
@@ -292,7 +294,9 @@ public String extractNextToken(AcceleratorTypeList payload) {
 
             @Override
             public Iterable<AcceleratorType> extractResources(AcceleratorTypeList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<AcceleratorType>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AddressStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AddressStubSettings.java
index e733e46cbb4f..b6f69e97dbd2 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AddressStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AddressStubSettings.java
@@ -258,7 +258,9 @@ public String extractNextToken(AddressAggregatedList payload) {
 
             @Override
             public Iterable<AddressesScopedList> extractResources(AddressAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<AddressesScopedList>of();
             }
           };
 
@@ -294,7 +296,9 @@ public String extractNextToken(AddressList payload) {
 
             @Override
             public Iterable<Address> extractResources(AddressList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Address>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AutoscalerStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AutoscalerStubSettings.java
index 4b0798f46bb4..e9c2f93ef490 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AutoscalerStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/AutoscalerStubSettings.java
@@ -278,7 +278,9 @@ public String extractNextToken(AutoscalerAggregatedList payload) {
             @Override
             public Iterable<AutoscalersScopedList> extractResources(
                 AutoscalerAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<AutoscalersScopedList>of();
             }
           };
 
@@ -314,7 +316,9 @@ public String extractNextToken(AutoscalerList payload) {
 
             @Override
             public Iterable<Autoscaler> extractResources(AutoscalerList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Autoscaler>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/BackendBucketStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/BackendBucketStubSettings.java
index 81d6c7ee2e92..22e4fe2f3e74 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/BackendBucketStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/BackendBucketStubSettings.java
@@ -288,7 +288,9 @@ public String extractNextToken(BackendBucketList payload) {
 
             @Override
             public Iterable<BackendBucket> extractResources(BackendBucketList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<BackendBucket>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/BackendServiceStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/BackendServiceStubSettings.java
index 070b57df28c1..2bb258460d52 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/BackendServiceStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/BackendServiceStubSettings.java
@@ -335,7 +335,9 @@ public String extractNextToken(BackendServiceAggregatedList payload) {
             @Override
             public Iterable<BackendServicesScopedList> extractResources(
                 BackendServiceAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<BackendServicesScopedList>of();
             }
           };
 
@@ -375,7 +377,9 @@ public String extractNextToken(BackendServiceList payload) {
 
             @Override
             public Iterable<BackendService> extractResources(BackendServiceList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<BackendService>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/DiskStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/DiskStubSettings.java
index fb9537e6e517..077821ff48a9 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/DiskStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/DiskStubSettings.java
@@ -279,7 +279,9 @@ public String extractNextToken(DiskAggregatedList payload) {
 
             @Override
             public Iterable<DisksScopedList> extractResources(DiskAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<DisksScopedList>of();
             }
           };
 
@@ -313,7 +315,9 @@ public String extractNextToken(DiskList payload) {
 
             @Override
             public Iterable<Disk> extractResources(DiskList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Disk>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/DiskTypeStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/DiskTypeStubSettings.java
index 8cd7818f1c6e..6d4d6a414027 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/DiskTypeStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/DiskTypeStubSettings.java
@@ -242,7 +242,9 @@ public String extractNextToken(DiskTypeAggregatedList payload) {
 
             @Override
             public Iterable<DiskTypesScopedList> extractResources(DiskTypeAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<DiskTypesScopedList>of();
             }
           };
 
@@ -278,7 +280,9 @@ public String extractNextToken(DiskTypeList payload) {
 
             @Override
             public Iterable<DiskType> extractResources(DiskTypeList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<DiskType>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/FirewallStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/FirewallStubSettings.java
index 9e7af23a14f8..a8c19ccd8a02 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/FirewallStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/FirewallStubSettings.java
@@ -252,7 +252,9 @@ public String extractNextToken(FirewallList payload) {
 
             @Override
             public Iterable<Firewall> extractResources(FirewallList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Firewall>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ForwardingRuleStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ForwardingRuleStubSettings.java
index 81707a48cd42..ed7877683728 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ForwardingRuleStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ForwardingRuleStubSettings.java
@@ -281,7 +281,9 @@ public String extractNextToken(ForwardingRuleAggregatedList payload) {
             @Override
             public Iterable<ForwardingRulesScopedList> extractResources(
                 ForwardingRuleAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<ForwardingRulesScopedList>of();
             }
           };
 
@@ -321,7 +323,9 @@ public String extractNextToken(ForwardingRuleList payload) {
 
             @Override
             public Iterable<ForwardingRule> extractResources(ForwardingRuleList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<ForwardingRule>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalAddressStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalAddressStubSettings.java
index 409943639634..e0b77e17371b 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalAddressStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalAddressStubSettings.java
@@ -244,7 +244,9 @@ public String extractNextToken(AddressList payload) {
 
             @Override
             public Iterable<Address> extractResources(AddressList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Address>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalForwardingRuleStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalForwardingRuleStubSettings.java
index 019b57dfeb79..77c2a0707107 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalForwardingRuleStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalForwardingRuleStubSettings.java
@@ -266,7 +266,9 @@ public String extractNextToken(ForwardingRuleList payload) {
 
             @Override
             public Iterable<ForwardingRule> extractResources(ForwardingRuleList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<ForwardingRule>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalOperationStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalOperationStubSettings.java
index 8dfeea1ad6b0..7b52e7d92180 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalOperationStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/GlobalOperationStubSettings.java
@@ -257,7 +257,9 @@ public String extractNextToken(OperationAggregatedList payload) {
             @Override
             public Iterable<OperationsScopedList> extractResources(
                 OperationAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<OperationsScopedList>of();
             }
           };
 
@@ -298,7 +300,9 @@ public String extractNextToken(OperationList payload) {
 
             @Override
             public Iterable<Operation> extractResources(OperationList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Operation>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HealthCheckStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HealthCheckStubSettings.java
index 11cdb64541fa..a31d115f77f6 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HealthCheckStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HealthCheckStubSettings.java
@@ -260,7 +260,9 @@ public String extractNextToken(HealthCheckList payload) {
 
             @Override
             public Iterable<HealthCheck> extractResources(HealthCheckList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<HealthCheck>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HttpHealthCheckStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HttpHealthCheckStubSettings.java
index 6ce448ba8aed..3187e71da07e 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HttpHealthCheckStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HttpHealthCheckStubSettings.java
@@ -270,7 +270,9 @@ public String extractNextToken(HttpHealthCheckList payload) {
 
             @Override
             public Iterable<HttpHealthCheck2> extractResources(HttpHealthCheckList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<HttpHealthCheck2>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HttpsHealthCheckStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HttpsHealthCheckStubSettings.java
index e32cc939ca47..5383e0566c3f 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HttpsHealthCheckStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/HttpsHealthCheckStubSettings.java
@@ -272,7 +272,9 @@ public String extractNextToken(HttpsHealthCheckList payload) {
 
             @Override
             public Iterable<HttpsHealthCheck2> extractResources(HttpsHealthCheckList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<HttpsHealthCheck2>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ImageStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ImageStubSettings.java
index 79e43f7cad0b..e3c32ae4c562 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ImageStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ImageStubSettings.java
@@ -258,7 +258,9 @@ public String extractNextToken(ImageList payload) {
 
             @Override
             public Iterable<Image> extractResources(ImageList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Image>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceGroupManagerStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceGroupManagerStubSettings.java
index 44a165ecc5c1..9fff6f166fc6 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceGroupManagerStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceGroupManagerStubSettings.java
@@ -367,7 +367,9 @@ public String extractNextToken(InstanceGroupManagerAggregatedList payload) {
             @Override
             public Iterable<InstanceGroupManagersScopedList> extractResources(
                 InstanceGroupManagerAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<InstanceGroupManagersScopedList>of();
             }
           };
 
@@ -411,7 +413,9 @@ public String extractNextToken(InstanceGroupManagerList payload) {
             @Override
             public Iterable<InstanceGroupManager> extractResources(
                 InstanceGroupManagerList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<InstanceGroupManager>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceGroupStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceGroupStubSettings.java
index 320cad8331f7..67f82374265e 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceGroupStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceGroupStubSettings.java
@@ -320,7 +320,9 @@ public String extractNextToken(InstanceGroupAggregatedList payload) {
             @Override
             public Iterable<InstanceGroupsScopedList> extractResources(
                 InstanceGroupAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<InstanceGroupsScopedList>of();
             }
           };
 
@@ -360,7 +362,9 @@ public String extractNextToken(InstanceGroupList payload) {
 
             @Override
             public Iterable<InstanceGroup> extractResources(InstanceGroupList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<InstanceGroup>of();
             }
           };
 
@@ -405,7 +409,9 @@ public String extractNextToken(InstanceGroupsListInstances payload) {
             @Override
             public Iterable<InstanceWithNamedPorts> extractResources(
                 InstanceGroupsListInstances payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<InstanceWithNamedPorts>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceStubSettings.java
index c061f6f268ee..7e3ce14f64aa 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceStubSettings.java
@@ -494,7 +494,9 @@ public String extractNextToken(InstanceAggregatedList payload) {
 
             @Override
             public Iterable<InstancesScopedList> extractResources(InstanceAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<InstancesScopedList>of();
             }
           };
 
@@ -530,7 +532,9 @@ public String extractNextToken(InstanceList payload) {
 
             @Override
             public Iterable<Instance> extractResources(InstanceList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Instance>of();
             }
           };
 
@@ -572,7 +576,9 @@ public String extractNextToken(InstanceListReferrers payload) {
 
             @Override
             public Iterable<Reference> extractResources(InstanceListReferrers payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Reference>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceTemplateStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceTemplateStubSettings.java
index 819de6dde783..e0fab0744c17 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceTemplateStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InstanceTemplateStubSettings.java
@@ -252,7 +252,9 @@ public String extractNextToken(InstanceTemplateList payload) {
 
             @Override
             public Iterable<InstanceTemplate> extractResources(InstanceTemplateList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<InstanceTemplate>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectAttachmentStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectAttachmentStubSettings.java
index 8721864b995e..d06aaa591cb3 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectAttachmentStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectAttachmentStubSettings.java
@@ -291,7 +291,9 @@ public String extractNextToken(InterconnectAttachmentAggregatedList payload) {
             @Override
             public Iterable<InterconnectAttachmentsScopedList> extractResources(
                 InterconnectAttachmentAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<InterconnectAttachmentsScopedList>of();
             }
           };
 
@@ -336,7 +338,9 @@ public String extractNextToken(InterconnectAttachmentList payload) {
             @Override
             public Iterable<InterconnectAttachment> extractResources(
                 InterconnectAttachmentList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<InterconnectAttachment>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectLocationStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectLocationStubSettings.java
index 2d8929b980de..fabb6e5f9de7 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectLocationStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectLocationStubSettings.java
@@ -234,7 +234,9 @@ public String extractNextToken(InterconnectLocationList payload) {
             @Override
             public Iterable<InterconnectLocation> extractResources(
                 InterconnectLocationList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<InterconnectLocation>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectStubSettings.java
index 7f7d7d43ee8a..5f6cdf330cda 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/InterconnectStubSettings.java
@@ -252,7 +252,9 @@ public String extractNextToken(InterconnectList payload) {
 
             @Override
             public Iterable<Interconnect> extractResources(InterconnectList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Interconnect>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/LicenseStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/LicenseStubSettings.java
index 1fc3748ed609..e5593a950bb0 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/LicenseStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/LicenseStubSettings.java
@@ -247,7 +247,9 @@ public String extractNextToken(LicensesListResponse payload) {
 
             @Override
             public Iterable<License> extractResources(LicensesListResponse payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<License>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/MachineTypeStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/MachineTypeStubSettings.java
index fdd22baca8b8..67399ce3b07b 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/MachineTypeStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/MachineTypeStubSettings.java
@@ -247,7 +247,9 @@ public String extractNextToken(MachineTypeAggregatedList payload) {
             @Override
             public Iterable<MachineTypesScopedList> extractResources(
                 MachineTypeAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<MachineTypesScopedList>of();
             }
           };
 
@@ -286,7 +288,9 @@ public String extractNextToken(MachineTypeList payload) {
 
             @Override
             public Iterable<MachineType> extractResources(MachineTypeList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<MachineType>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NetworkStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NetworkStubSettings.java
index e025cedc2c13..900d2f55491f 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NetworkStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NetworkStubSettings.java
@@ -272,7 +272,9 @@ public String extractNextToken(NetworkList payload) {
 
             @Override
             public Iterable<Network> extractResources(NetworkList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Network>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeGroupStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeGroupStubSettings.java
index 552a430f9178..c847ad3b3c99 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeGroupStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeGroupStubSettings.java
@@ -305,7 +305,9 @@ public String extractNextToken(NodeGroupAggregatedList payload) {
             @Override
             public Iterable<NodeGroupsScopedList> extractResources(
                 NodeGroupAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<NodeGroupsScopedList>of();
             }
           };
 
@@ -341,7 +343,9 @@ public String extractNextToken(NodeGroupList payload) {
 
             @Override
             public Iterable<NodeGroup> extractResources(NodeGroupList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<NodeGroup>of();
             }
           };
 
@@ -381,7 +385,9 @@ public String extractNextToken(NodeGroupsListNodes payload) {
 
             @Override
             public Iterable<NodeGroupNode> extractResources(NodeGroupsListNodes payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<NodeGroupNode>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeTemplateStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeTemplateStubSettings.java
index 61b0a8f3999a..211e6ad7a603 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeTemplateStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeTemplateStubSettings.java
@@ -267,7 +267,9 @@ public String extractNextToken(NodeTemplateAggregatedList payload) {
             @Override
             public Iterable<NodeTemplatesScopedList> extractResources(
                 NodeTemplateAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<NodeTemplatesScopedList>of();
             }
           };
 
@@ -306,7 +308,9 @@ public String extractNextToken(NodeTemplateList payload) {
 
             @Override
             public Iterable<NodeTemplate> extractResources(NodeTemplateList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<NodeTemplate>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeTypeStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeTypeStubSettings.java
index bb7f94471a27..64a788ed5d72 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeTypeStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/NodeTypeStubSettings.java
@@ -242,7 +242,9 @@ public String extractNextToken(NodeTypeAggregatedList payload) {
 
             @Override
             public Iterable<NodeTypesScopedList> extractResources(NodeTypeAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<NodeTypesScopedList>of();
             }
           };
 
@@ -278,7 +280,9 @@ public String extractNextToken(NodeTypeList payload) {
 
             @Override
             public Iterable<NodeType> extractResources(NodeTypeList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<NodeType>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ProjectStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ProjectStubSettings.java
index f5e5a246ddc6..77970912150b 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ProjectStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ProjectStubSettings.java
@@ -343,7 +343,9 @@ public String extractNextToken(ProjectsGetXpnResources payload) {
 
             @Override
             public Iterable<XpnResourceId> extractResources(ProjectsGetXpnResources payload) {
-              return payload.getResourcesList();
+              return payload.getResourcesList() != null
+                  ? payload.getResourcesList()
+                  : ImmutableList.<XpnResourceId>of();
             }
           };
 
@@ -383,7 +385,9 @@ public String extractNextToken(XpnHostList payload) {
 
             @Override
             public Iterable<Project> extractResources(XpnHostList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Project>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionAutoscalerStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionAutoscalerStubSettings.java
index 4e81bac5cdc1..70a37d30458b 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionAutoscalerStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionAutoscalerStubSettings.java
@@ -272,7 +272,9 @@ public String extractNextToken(RegionAutoscalerList payload) {
 
             @Override
             public Iterable<Autoscaler> extractResources(RegionAutoscalerList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Autoscaler>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionBackendServiceStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionBackendServiceStubSettings.java
index 46aca507d5a1..355ccbb9093a 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionBackendServiceStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionBackendServiceStubSettings.java
@@ -289,7 +289,9 @@ public String extractNextToken(BackendServiceList payload) {
 
             @Override
             public Iterable<BackendService> extractResources(BackendServiceList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<BackendService>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionCommitmentStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionCommitmentStubSettings.java
index 4f93e74feedc..9d402966b895 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionCommitmentStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionCommitmentStubSettings.java
@@ -261,7 +261,9 @@ public String extractNextToken(CommitmentAggregatedList payload) {
             @Override
             public Iterable<CommitmentsScopedList> extractResources(
                 CommitmentAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<CommitmentsScopedList>of();
             }
           };
 
@@ -302,7 +304,9 @@ public String extractNextToken(CommitmentList payload) {
 
             @Override
             public Iterable<Commitment> extractResources(CommitmentList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Commitment>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionDiskStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionDiskStubSettings.java
index b2f9119eff36..60d74ec4f644 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionDiskStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionDiskStubSettings.java
@@ -277,7 +277,9 @@ public String extractNextToken(DiskList payload) {
 
             @Override
             public Iterable<Disk> extractResources(DiskList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Disk>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionDiskTypeStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionDiskTypeStubSettings.java
index 05f773d9ef49..8bbd57201f52 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionDiskTypeStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionDiskTypeStubSettings.java
@@ -224,7 +224,9 @@ public String extractNextToken(RegionDiskTypeList payload) {
 
             @Override
             public Iterable<DiskType> extractResources(RegionDiskTypeList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<DiskType>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionInstanceGroupManagerStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionInstanceGroupManagerStubSettings.java
index 601d37d866fa..86b2b3d309d9 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionInstanceGroupManagerStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionInstanceGroupManagerStubSettings.java
@@ -361,7 +361,9 @@ public String extractNextToken(RegionInstanceGroupManagerList payload) {
             @Override
             public Iterable<InstanceGroupManager> extractResources(
                 RegionInstanceGroupManagerList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<InstanceGroupManager>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionInstanceGroupStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionInstanceGroupStubSettings.java
index 17d4c0d42d97..e38683be254f 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionInstanceGroupStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionInstanceGroupStubSettings.java
@@ -261,7 +261,9 @@ public String extractNextToken(RegionInstanceGroupList payload) {
 
             @Override
             public Iterable<InstanceGroup> extractResources(RegionInstanceGroupList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<InstanceGroup>of();
             }
           };
 
@@ -306,7 +308,9 @@ public String extractNextToken(RegionInstanceGroupsListInstances payload) {
             @Override
             public Iterable<InstanceWithNamedPorts> extractResources(
                 RegionInstanceGroupsListInstances payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<InstanceWithNamedPorts>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionOperationStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionOperationStubSettings.java
index 270ec87bf321..bf56763152c7 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionOperationStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionOperationStubSettings.java
@@ -236,7 +236,9 @@ public String extractNextToken(OperationList payload) {
 
             @Override
             public Iterable<Operation> extractResources(OperationList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Operation>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionStubSettings.java
index 45044fc42d3a..6768a9123426 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RegionStubSettings.java
@@ -218,7 +218,9 @@ public String extractNextToken(RegionList payload) {
 
             @Override
             public Iterable<Region> extractResources(RegionList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Region>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RouteStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RouteStubSettings.java
index f37082e4f972..5aeabc21a44b 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RouteStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RouteStubSettings.java
@@ -234,7 +234,9 @@ public String extractNextToken(RouteList payload) {
 
             @Override
             public Iterable<Route> extractResources(RouteList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Route>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RouterStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RouterStubSettings.java
index 1c379f2dc19a..d513b97d8473 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RouterStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/RouterStubSettings.java
@@ -296,7 +296,9 @@ public String extractNextToken(RouterAggregatedList payload) {
 
             @Override
             public Iterable<RoutersScopedList> extractResources(RouterAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<RoutersScopedList>of();
             }
           };
 
@@ -332,7 +334,9 @@ public String extractNextToken(RouterList payload) {
 
             @Override
             public Iterable<Router> extractResources(RouterList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Router>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SecurityPolicyStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SecurityPolicyStubSettings.java
index 1244eca214d6..290ff2eb0410 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SecurityPolicyStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SecurityPolicyStubSettings.java
@@ -301,7 +301,9 @@ public String extractNextToken(SecurityPolicyList payload) {
 
             @Override
             public Iterable<SecurityPolicy> extractResources(SecurityPolicyList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<SecurityPolicy>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SnapshotStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SnapshotStubSettings.java
index a7646118c60d..4139d24dcb11 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SnapshotStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SnapshotStubSettings.java
@@ -237,7 +237,9 @@ public String extractNextToken(SnapshotList payload) {
 
             @Override
             public Iterable<Snapshot> extractResources(SnapshotList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Snapshot>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SslCertificateStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SslCertificateStubSettings.java
index fe0cf6eafb07..f1ac3b87aa72 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SslCertificateStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SslCertificateStubSettings.java
@@ -248,7 +248,9 @@ public String extractNextToken(SslCertificateList payload) {
 
             @Override
             public Iterable<SslCertificate> extractResources(SslCertificateList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<SslCertificate>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SslPolicyStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SslPolicyStubSettings.java
index 48096607a206..501adab34abb 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SslPolicyStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SslPolicyStubSettings.java
@@ -259,7 +259,9 @@ public String extractNextToken(SslPoliciesList payload) {
 
             @Override
             public Iterable<SslPolicy> extractResources(SslPoliciesList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<SslPolicy>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SubnetworkStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SubnetworkStubSettings.java
index 3a57b4df4fa9..a932375cfb86 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SubnetworkStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/SubnetworkStubSettings.java
@@ -309,7 +309,9 @@ public String extractNextToken(SubnetworkAggregatedList payload) {
             @Override
             public Iterable<SubnetworksScopedList> extractResources(
                 SubnetworkAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<SubnetworksScopedList>of();
             }
           };
 
@@ -345,7 +347,9 @@ public String extractNextToken(SubnetworkList payload) {
 
             @Override
             public Iterable<Subnetwork> extractResources(SubnetworkList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Subnetwork>of();
             }
           };
 
@@ -389,7 +393,9 @@ public String extractNextToken(UsableSubnetworksAggregatedList payload) {
             @Override
             public Iterable<UsableSubnetwork> extractResources(
                 UsableSubnetworksAggregatedList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<UsableSubnetwork>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetHttpProxyStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetHttpProxyStubSettings.java
index adf9b921b5dd..e877db9c7c74 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetHttpProxyStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetHttpProxyStubSettings.java
@@ -260,7 +260,9 @@ public String extractNextToken(TargetHttpProxyList payload) {
 
             @Override
             public Iterable<TargetHttpProxy> extractResources(TargetHttpProxyList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<TargetHttpProxy>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetHttpsProxyStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetHttpsProxyStubSettings.java
index c006b8b28df4..788d33478ae4 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetHttpsProxyStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetHttpsProxyStubSettings.java
@@ -295,7 +295,9 @@ public String extractNextToken(TargetHttpsProxyList payload) {
 
             @Override
             public Iterable<TargetHttpsProxy> extractResources(TargetHttpsProxyList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<TargetHttpsProxy>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetInstanceStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetInstanceStubSettings.java
index 4ada09b98847..0345621f5879 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetInstanceStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetInstanceStubSettings.java
@@ -271,7 +271,9 @@ public String extractNextToken(TargetInstanceAggregatedList payload) {
             @Override
             public Iterable<TargetInstancesScopedList> extractResources(
                 TargetInstanceAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<TargetInstancesScopedList>of();
             }
           };
 
@@ -311,7 +313,9 @@ public String extractNextToken(TargetInstanceList payload) {
 
             @Override
             public Iterable<TargetInstance> extractResources(TargetInstanceList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<TargetInstance>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetPoolStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetPoolStubSettings.java
index 239def189ab1..1a4293a01143 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetPoolStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetPoolStubSettings.java
@@ -324,7 +324,9 @@ public String extractNextToken(TargetPoolAggregatedList payload) {
             @Override
             public Iterable<TargetPoolsScopedList> extractResources(
                 TargetPoolAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<TargetPoolsScopedList>of();
             }
           };
 
@@ -360,7 +362,9 @@ public String extractNextToken(TargetPoolList payload) {
 
             @Override
             public Iterable<TargetPool> extractResources(TargetPoolList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<TargetPool>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetSslProxyStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetSslProxyStubSettings.java
index 1b9d9d804bce..99cd6a9cbf27 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetSslProxyStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetSslProxyStubSettings.java
@@ -294,7 +294,9 @@ public String extractNextToken(TargetSslProxyList payload) {
 
             @Override
             public Iterable<TargetSslProxy> extractResources(TargetSslProxyList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<TargetSslProxy>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetTcpProxyStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetTcpProxyStubSettings.java
index 211cb213e68e..b9e1ffaca8ae 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetTcpProxyStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetTcpProxyStubSettings.java
@@ -272,7 +272,9 @@ public String extractNextToken(TargetTcpProxyList payload) {
 
             @Override
             public Iterable<TargetTcpProxy> extractResources(TargetTcpProxyList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<TargetTcpProxy>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetVpnGatewayStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetVpnGatewayStubSettings.java
index c25b3c56abdf..3b7e08cf76b8 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetVpnGatewayStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/TargetVpnGatewayStubSettings.java
@@ -273,7 +273,9 @@ public String extractNextToken(TargetVpnGatewayAggregatedList payload) {
             @Override
             public Iterable<TargetVpnGatewaysScopedList> extractResources(
                 TargetVpnGatewayAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<TargetVpnGatewaysScopedList>of();
             }
           };
 
@@ -315,7 +317,9 @@ public String extractNextToken(TargetVpnGatewayList payload) {
 
             @Override
             public Iterable<TargetVpnGateway> extractResources(TargetVpnGatewayList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<TargetVpnGateway>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/UrlMapStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/UrlMapStubSettings.java
index 9be5fe064fb2..6127ec98aca7 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/UrlMapStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/UrlMapStubSettings.java
@@ -272,7 +272,9 @@ public String extractNextToken(UrlMapList payload) {
 
             @Override
             public Iterable<UrlMap> extractResources(UrlMapList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<UrlMap>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/VpnTunnelStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/VpnTunnelStubSettings.java
index e62fa9c01226..73223955caab 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/VpnTunnelStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/VpnTunnelStubSettings.java
@@ -261,7 +261,9 @@ public String extractNextToken(VpnTunnelAggregatedList payload) {
             @Override
             public Iterable<VpnTunnelsScopedList> extractResources(
                 VpnTunnelAggregatedList payload) {
-              return payload.getItemsMap().values();
+              return payload.getItemsMap() != null
+                  ? payload.getItemsMap().values()
+                  : ImmutableList.<VpnTunnelsScopedList>of();
             }
           };
 
@@ -297,7 +299,9 @@ public String extractNextToken(VpnTunnelList payload) {
 
             @Override
             public Iterable<VpnTunnel> extractResources(VpnTunnelList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<VpnTunnel>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ZoneOperationStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ZoneOperationStubSettings.java
index dc9421bdf3c9..cb5d1499bd1d 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ZoneOperationStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ZoneOperationStubSettings.java
@@ -231,7 +231,9 @@ public String extractNextToken(OperationList payload) {
 
             @Override
             public Iterable<Operation> extractResources(OperationList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Operation>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ZoneStubSettings.java b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ZoneStubSettings.java
index cf5ac03aa4e0..b797979493ef 100644
--- a/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ZoneStubSettings.java
+++ b/google-cloud-clients/google-cloud-compute/src/main/java/com/google/cloud/compute/v1/stub/ZoneStubSettings.java
@@ -216,7 +216,9 @@ public String extractNextToken(ZoneList payload) {
 
             @Override
             public Iterable<Zone> extractResources(ZoneList payload) {
-              return payload.getItemsList();
+              return payload.getItemsList() != null
+                  ? payload.getItemsList()
+                  : ImmutableList.<Zone>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-containeranalysis/src/main/java/com/google/cloud/devtools/containeranalysis/v1beta1/stub/ContainerAnalysisV1Beta1StubSettings.java b/google-cloud-clients/google-cloud-containeranalysis/src/main/java/com/google/cloud/devtools/containeranalysis/v1beta1/stub/ContainerAnalysisV1Beta1StubSettings.java
index ace17ac7200c..0db203d39adc 100644
--- a/google-cloud-clients/google-cloud-containeranalysis/src/main/java/com/google/cloud/devtools/containeranalysis/v1beta1/stub/ContainerAnalysisV1Beta1StubSettings.java
+++ b/google-cloud-clients/google-cloud-containeranalysis/src/main/java/com/google/cloud/devtools/containeranalysis/v1beta1/stub/ContainerAnalysisV1Beta1StubSettings.java
@@ -245,7 +245,9 @@ public String extractNextToken(ListScanConfigsResponse payload) {
 
             @Override
             public Iterable<ScanConfig> extractResources(ListScanConfigsResponse payload) {
-              return payload.getScanConfigsList();
+              return payload.getScanConfigsList() != null
+                  ? payload.getScanConfigsList()
+                  : ImmutableList.<ScanConfig>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-containeranalysis/src/main/java/com/google/cloud/devtools/containeranalysis/v1beta1/stub/GrafeasV1Beta1StubSettings.java b/google-cloud-clients/google-cloud-containeranalysis/src/main/java/com/google/cloud/devtools/containeranalysis/v1beta1/stub/GrafeasV1Beta1StubSettings.java
index 419ecfe0d5ed..e9240bdef06f 100644
--- a/google-cloud-clients/google-cloud-containeranalysis/src/main/java/com/google/cloud/devtools/containeranalysis/v1beta1/stub/GrafeasV1Beta1StubSettings.java
+++ b/google-cloud-clients/google-cloud-containeranalysis/src/main/java/com/google/cloud/devtools/containeranalysis/v1beta1/stub/GrafeasV1Beta1StubSettings.java
@@ -336,7 +336,9 @@ public String extractNextToken(ListOccurrencesResponse payload) {
 
             @Override
             public Iterable<Occurrence> extractResources(ListOccurrencesResponse payload) {
-              return payload.getOccurrencesList();
+              return payload.getOccurrencesList() != null
+                  ? payload.getOccurrencesList()
+                  : ImmutableList.<Occurrence>of();
             }
           };
 
@@ -370,7 +372,9 @@ public String extractNextToken(ListNotesResponse payload) {
 
             @Override
             public Iterable<Note> extractResources(ListNotesResponse payload) {
-              return payload.getNotesList();
+              return payload.getNotesList() != null
+                  ? payload.getNotesList()
+                  : ImmutableList.<Note>of();
             }
           };
 
@@ -408,7 +412,9 @@ public String extractNextToken(ListNoteOccurrencesResponse payload) {
 
             @Override
             public Iterable<Occurrence> extractResources(ListNoteOccurrencesResponse payload) {
-              return payload.getOccurrencesList();
+              return payload.getOccurrencesList() != null
+                  ? payload.getOccurrencesList()
+                  : ImmutableList.<Occurrence>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1/stub/ClusterControllerStubSettings.java b/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1/stub/ClusterControllerStubSettings.java
index 85b2d5e65b39..ee4eca3d3a5b 100644
--- a/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1/stub/ClusterControllerStubSettings.java
+++ b/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1/stub/ClusterControllerStubSettings.java
@@ -283,7 +283,9 @@ public String extractNextToken(ListClustersResponse payload) {
 
             @Override
             public Iterable<Cluster> extractResources(ListClustersResponse payload) {
-              return payload.getClustersList();
+              return payload.getClustersList() != null
+                  ? payload.getClustersList()
+                  : ImmutableList.<Cluster>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1/stub/JobControllerStubSettings.java b/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1/stub/JobControllerStubSettings.java
index 509a5121f2d5..8e86809108cf 100644
--- a/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1/stub/JobControllerStubSettings.java
+++ b/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1/stub/JobControllerStubSettings.java
@@ -235,7 +235,9 @@ public String extractNextToken(ListJobsResponse payload) {
 
             @Override
             public Iterable<Job> extractResources(ListJobsResponse payload) {
-              return payload.getJobsList();
+              return payload.getJobsList() != null
+                  ? payload.getJobsList()
+                  : ImmutableList.<Job>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/ClusterControllerStubSettings.java b/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/ClusterControllerStubSettings.java
index 691e2e00f732..5e1da5df3131 100644
--- a/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/ClusterControllerStubSettings.java
+++ b/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/ClusterControllerStubSettings.java
@@ -283,7 +283,9 @@ public String extractNextToken(ListClustersResponse payload) {
 
             @Override
             public Iterable<Cluster> extractResources(ListClustersResponse payload) {
-              return payload.getClustersList();
+              return payload.getClustersList() != null
+                  ? payload.getClustersList()
+                  : ImmutableList.<Cluster>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/JobControllerStubSettings.java b/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/JobControllerStubSettings.java
index 9ec7538a4627..e645d2d7e28f 100644
--- a/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/JobControllerStubSettings.java
+++ b/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/JobControllerStubSettings.java
@@ -235,7 +235,9 @@ public String extractNextToken(ListJobsResponse payload) {
 
             @Override
             public Iterable<Job> extractResources(ListJobsResponse payload) {
-              return payload.getJobsList();
+              return payload.getJobsList() != null
+                  ? payload.getJobsList()
+                  : ImmutableList.<Job>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/WorkflowTemplateServiceStubSettings.java b/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/WorkflowTemplateServiceStubSettings.java
index d0915d036d6f..07e55b175947 100644
--- a/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/WorkflowTemplateServiceStubSettings.java
+++ b/google-cloud-clients/google-cloud-dataproc/src/main/java/com/google/cloud/dataproc/v1beta2/stub/WorkflowTemplateServiceStubSettings.java
@@ -272,7 +272,9 @@ public String extractNextToken(ListWorkflowTemplatesResponse payload) {
             @Override
             public Iterable<WorkflowTemplate> extractResources(
                 ListWorkflowTemplatesResponse payload) {
-              return payload.getTemplatesList();
+              return payload.getTemplatesList() != null
+                  ? payload.getTemplatesList()
+                  : ImmutableList.<WorkflowTemplate>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/AgentsStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/AgentsStubSettings.java
index 0a2c3699c540..7ab25a63b13a 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/AgentsStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/AgentsStubSettings.java
@@ -278,7 +278,9 @@ public String extractNextToken(SearchAgentsResponse payload) {
 
             @Override
             public Iterable<Agent> extractResources(SearchAgentsResponse payload) {
-              return payload.getAgentsList();
+              return payload.getAgentsList() != null
+                  ? payload.getAgentsList()
+                  : ImmutableList.<Agent>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/ContextsStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/ContextsStubSettings.java
index c4ed27094f81..8f883dae3947 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/ContextsStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/ContextsStubSettings.java
@@ -235,7 +235,9 @@ public String extractNextToken(ListContextsResponse payload) {
 
             @Override
             public Iterable<Context> extractResources(ListContextsResponse payload) {
-              return payload.getContextsList();
+              return payload.getContextsList() != null
+                  ? payload.getContextsList()
+                  : ImmutableList.<Context>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/EntityTypesStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/EntityTypesStubSettings.java
index 894cae3c3d8a..069ec3342d0d 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/EntityTypesStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/EntityTypesStubSettings.java
@@ -343,7 +343,9 @@ public String extractNextToken(ListEntityTypesResponse payload) {
 
             @Override
             public Iterable<EntityType> extractResources(ListEntityTypesResponse payload) {
-              return payload.getEntityTypesList();
+              return payload.getEntityTypesList() != null
+                  ? payload.getEntityTypesList()
+                  : ImmutableList.<EntityType>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/IntentsStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/IntentsStubSettings.java
index d5b02b07e881..0e7ba5ca03a1 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/IntentsStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/IntentsStubSettings.java
@@ -271,7 +271,9 @@ public String extractNextToken(ListIntentsResponse payload) {
 
             @Override
             public Iterable<Intent> extractResources(ListIntentsResponse payload) {
-              return payload.getIntentsList();
+              return payload.getIntentsList() != null
+                  ? payload.getIntentsList()
+                  : ImmutableList.<Intent>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/SessionEntityTypesStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/SessionEntityTypesStubSettings.java
index 34578fe8a735..be6e0322e13d 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/SessionEntityTypesStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2/stub/SessionEntityTypesStubSettings.java
@@ -246,7 +246,9 @@ public String extractNextToken(ListSessionEntityTypesResponse payload) {
             @Override
             public Iterable<SessionEntityType> extractResources(
                 ListSessionEntityTypesResponse payload) {
-              return payload.getSessionEntityTypesList();
+              return payload.getSessionEntityTypesList() != null
+                  ? payload.getSessionEntityTypesList()
+                  : ImmutableList.<SessionEntityType>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/AgentsStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/AgentsStubSettings.java
index 903679697993..ca5e87afe6de 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/AgentsStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/AgentsStubSettings.java
@@ -278,7 +278,9 @@ public String extractNextToken(SearchAgentsResponse payload) {
 
             @Override
             public Iterable<Agent> extractResources(SearchAgentsResponse payload) {
-              return payload.getAgentsList();
+              return payload.getAgentsList() != null
+                  ? payload.getAgentsList()
+                  : ImmutableList.<Agent>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/ContextsStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/ContextsStubSettings.java
index 9696b4eb22b9..146c9332b74d 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/ContextsStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/ContextsStubSettings.java
@@ -235,7 +235,9 @@ public String extractNextToken(ListContextsResponse payload) {
 
             @Override
             public Iterable<Context> extractResources(ListContextsResponse payload) {
-              return payload.getContextsList();
+              return payload.getContextsList() != null
+                  ? payload.getContextsList()
+                  : ImmutableList.<Context>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/DocumentsStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/DocumentsStubSettings.java
index b7c14c5a4ec8..2f3be7ded502 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/DocumentsStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/DocumentsStubSettings.java
@@ -245,7 +245,9 @@ public String extractNextToken(ListDocumentsResponse payload) {
 
             @Override
             public Iterable<Document> extractResources(ListDocumentsResponse payload) {
-              return payload.getDocumentsList();
+              return payload.getDocumentsList() != null
+                  ? payload.getDocumentsList()
+                  : ImmutableList.<Document>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/EntityTypesStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/EntityTypesStubSettings.java
index b89de7ad6286..c34ce42daabc 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/EntityTypesStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/EntityTypesStubSettings.java
@@ -343,7 +343,9 @@ public String extractNextToken(ListEntityTypesResponse payload) {
 
             @Override
             public Iterable<EntityType> extractResources(ListEntityTypesResponse payload) {
-              return payload.getEntityTypesList();
+              return payload.getEntityTypesList() != null
+                  ? payload.getEntityTypesList()
+                  : ImmutableList.<EntityType>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/IntentsStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/IntentsStubSettings.java
index e0f9267bd893..ededdc6d5492 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/IntentsStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/IntentsStubSettings.java
@@ -271,7 +271,9 @@ public String extractNextToken(ListIntentsResponse payload) {
 
             @Override
             public Iterable<Intent> extractResources(ListIntentsResponse payload) {
-              return payload.getIntentsList();
+              return payload.getIntentsList() != null
+                  ? payload.getIntentsList()
+                  : ImmutableList.<Intent>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/KnowledgeBasesStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/KnowledgeBasesStubSettings.java
index 989875767d4a..4294f52f4aa8 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/KnowledgeBasesStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/KnowledgeBasesStubSettings.java
@@ -227,7 +227,9 @@ public String extractNextToken(ListKnowledgeBasesResponse payload) {
 
             @Override
             public Iterable<KnowledgeBase> extractResources(ListKnowledgeBasesResponse payload) {
-              return payload.getKnowledgeBasesList();
+              return payload.getKnowledgeBasesList() != null
+                  ? payload.getKnowledgeBasesList()
+                  : ImmutableList.<KnowledgeBase>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/SessionEntityTypesStubSettings.java b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/SessionEntityTypesStubSettings.java
index d515014c0716..a3a4fce3f92f 100644
--- a/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/SessionEntityTypesStubSettings.java
+++ b/google-cloud-clients/google-cloud-dialogflow/src/main/java/com/google/cloud/dialogflow/v2beta1/stub/SessionEntityTypesStubSettings.java
@@ -246,7 +246,9 @@ public String extractNextToken(ListSessionEntityTypesResponse payload) {
             @Override
             public Iterable<SessionEntityType> extractResources(
                 ListSessionEntityTypesResponse payload) {
-              return payload.getSessionEntityTypesList();
+              return payload.getSessionEntityTypesList() != null
+                  ? payload.getSessionEntityTypesList()
+                  : ImmutableList.<SessionEntityType>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-dlp/src/main/java/com/google/cloud/dlp/v2/stub/DlpServiceStubSettings.java b/google-cloud-clients/google-cloud-dlp/src/main/java/com/google/cloud/dlp/v2/stub/DlpServiceStubSettings.java
index e8cafcd8c575..9ed4f2cc88f9 100644
--- a/google-cloud-clients/google-cloud-dlp/src/main/java/com/google/cloud/dlp/v2/stub/DlpServiceStubSettings.java
+++ b/google-cloud-clients/google-cloud-dlp/src/main/java/com/google/cloud/dlp/v2/stub/DlpServiceStubSettings.java
@@ -495,7 +495,9 @@ public String extractNextToken(ListInspectTemplatesResponse payload) {
             @Override
             public Iterable<InspectTemplate> extractResources(
                 ListInspectTemplatesResponse payload) {
-              return payload.getInspectTemplatesList();
+              return payload.getInspectTemplatesList() != null
+                  ? payload.getInspectTemplatesList()
+                  : ImmutableList.<InspectTemplate>of();
             }
           };
 
@@ -537,7 +539,9 @@ public String extractNextToken(ListDeidentifyTemplatesResponse payload) {
             @Override
             public Iterable<DeidentifyTemplate> extractResources(
                 ListDeidentifyTemplatesResponse payload) {
-              return payload.getDeidentifyTemplatesList();
+              return payload.getDeidentifyTemplatesList() != null
+                  ? payload.getDeidentifyTemplatesList()
+                  : ImmutableList.<DeidentifyTemplate>of();
             }
           };
 
@@ -571,7 +575,9 @@ public String extractNextToken(ListDlpJobsResponse payload) {
 
             @Override
             public Iterable<DlpJob> extractResources(ListDlpJobsResponse payload) {
-              return payload.getJobsList();
+              return payload.getJobsList() != null
+                  ? payload.getJobsList()
+                  : ImmutableList.<DlpJob>of();
             }
           };
 
@@ -608,7 +614,9 @@ public String extractNextToken(ListJobTriggersResponse payload) {
 
             @Override
             public Iterable<JobTrigger> extractResources(ListJobTriggersResponse payload) {
-              return payload.getJobTriggersList();
+              return payload.getJobTriggersList() != null
+                  ? payload.getJobTriggersList()
+                  : ImmutableList.<JobTrigger>of();
             }
           };
 
@@ -646,7 +654,9 @@ public String extractNextToken(ListStoredInfoTypesResponse payload) {
 
             @Override
             public Iterable<StoredInfoType> extractResources(ListStoredInfoTypesResponse payload) {
-              return payload.getStoredInfoTypesList();
+              return payload.getStoredInfoTypesList() != null
+                  ? payload.getStoredInfoTypesList()
+                  : ImmutableList.<StoredInfoType>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-errorreporting/src/main/java/com/google/cloud/errorreporting/v1beta1/stub/ErrorStatsServiceStubSettings.java b/google-cloud-clients/google-cloud-errorreporting/src/main/java/com/google/cloud/errorreporting/v1beta1/stub/ErrorStatsServiceStubSettings.java
index 5a44d666c8f2..777fce58d494 100644
--- a/google-cloud-clients/google-cloud-errorreporting/src/main/java/com/google/cloud/errorreporting/v1beta1/stub/ErrorStatsServiceStubSettings.java
+++ b/google-cloud-clients/google-cloud-errorreporting/src/main/java/com/google/cloud/errorreporting/v1beta1/stub/ErrorStatsServiceStubSettings.java
@@ -222,7 +222,9 @@ public String extractNextToken(ListGroupStatsResponse payload) {
 
             @Override
             public Iterable<ErrorGroupStats> extractResources(ListGroupStatsResponse payload) {
-              return payload.getErrorGroupStatsList();
+              return payload.getErrorGroupStatsList() != null
+                  ? payload.getErrorGroupStatsList()
+                  : ImmutableList.<ErrorGroupStats>of();
             }
           };
 
@@ -256,7 +258,9 @@ public String extractNextToken(ListEventsResponse payload) {
 
             @Override
             public Iterable<ErrorEvent> extractResources(ListEventsResponse payload) {
-              return payload.getErrorEventsList();
+              return payload.getErrorEventsList() != null
+                  ? payload.getErrorEventsList()
+                  : ImmutableList.<ErrorEvent>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-firestore/src/main/java/com/google/cloud/firestore/v1beta1/stub/FirestoreStubSettings.java b/google-cloud-clients/google-cloud-firestore/src/main/java/com/google/cloud/firestore/v1beta1/stub/FirestoreStubSettings.java
index 36eac47a77c8..43366fcc07c1 100644
--- a/google-cloud-clients/google-cloud-firestore/src/main/java/com/google/cloud/firestore/v1beta1/stub/FirestoreStubSettings.java
+++ b/google-cloud-clients/google-cloud-firestore/src/main/java/com/google/cloud/firestore/v1beta1/stub/FirestoreStubSettings.java
@@ -312,7 +312,9 @@ public String extractNextToken(ListDocumentsResponse payload) {
 
             @Override
             public Iterable<Document> extractResources(ListDocumentsResponse payload) {
-              return payload.getDocumentsList();
+              return payload.getDocumentsList() != null
+                  ? payload.getDocumentsList()
+                  : ImmutableList.<Document>of();
             }
           };
 
@@ -349,7 +351,9 @@ public String extractNextToken(ListCollectionIdsResponse payload) {
 
             @Override
             public Iterable<String> extractResources(ListCollectionIdsResponse payload) {
-              return payload.getCollectionIdsList();
+              return payload.getCollectionIdsList() != null
+                  ? payload.getCollectionIdsList()
+                  : ImmutableList.<String>of();
             }
           };
 
@@ -566,7 +570,7 @@ private static Builder initDefaults(Builder builder) {
       builder
           .runQuerySettings()
           .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("idempotent"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("default"));
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("streaming"));
 
       builder
           .listCollectionIdsSettings()
diff --git a/google-cloud-clients/google-cloud-kms/src/main/java/com/google/cloud/kms/v1/stub/KeyManagementServiceStubSettings.java b/google-cloud-clients/google-cloud-kms/src/main/java/com/google/cloud/kms/v1/stub/KeyManagementServiceStubSettings.java
index 6167c54a1311..4937a2cfa5bd 100644
--- a/google-cloud-clients/google-cloud-kms/src/main/java/com/google/cloud/kms/v1/stub/KeyManagementServiceStubSettings.java
+++ b/google-cloud-clients/google-cloud-kms/src/main/java/com/google/cloud/kms/v1/stub/KeyManagementServiceStubSettings.java
@@ -405,7 +405,9 @@ public String extractNextToken(ListKeyRingsResponse payload) {
 
             @Override
             public Iterable<KeyRing> extractResources(ListKeyRingsResponse payload) {
-              return payload.getKeyRingsList();
+              return payload.getKeyRingsList() != null
+                  ? payload.getKeyRingsList()
+                  : ImmutableList.<KeyRing>of();
             }
           };
 
@@ -440,7 +442,9 @@ public String extractNextToken(ListCryptoKeysResponse payload) {
 
             @Override
             public Iterable<CryptoKey> extractResources(ListCryptoKeysResponse payload) {
-              return payload.getCryptoKeysList();
+              return payload.getCryptoKeysList() != null
+                  ? payload.getCryptoKeysList()
+                  : ImmutableList.<CryptoKey>of();
             }
           };
 
@@ -479,7 +483,9 @@ public String extractNextToken(ListCryptoKeyVersionsResponse payload) {
             @Override
             public Iterable<CryptoKeyVersion> extractResources(
                 ListCryptoKeyVersionsResponse payload) {
-              return payload.getCryptoKeyVersionsList();
+              return payload.getCryptoKeyVersionsList() != null
+                  ? payload.getCryptoKeyVersionsList()
+                  : ImmutableList.<CryptoKeyVersion>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-kms/src/test/java/com/google/cloud/kms/v1/KeyManagementServiceClientTest.java b/google-cloud-clients/google-cloud-kms/src/test/java/com/google/cloud/kms/v1/KeyManagementServiceClientTest.java
index 462c2ac52c5c..2a63e8c9cc9c 100644
--- a/google-cloud-clients/google-cloud-kms/src/test/java/com/google/cloud/kms/v1/KeyManagementServiceClientTest.java
+++ b/google-cloud-clients/google-cloud-kms/src/test/java/com/google/cloud/kms/v1/KeyManagementServiceClientTest.java
@@ -26,7 +26,6 @@
 import com.google.api.gax.grpc.testing.MockServiceHelper;
 import com.google.api.gax.rpc.ApiClientHeaderProvider;
 import com.google.api.gax.rpc.InvalidArgumentException;
-import com.google.cloud.kms.v1.CryptoKey.CryptoKeyPurpose;
 import com.google.common.collect.Lists;
 import com.google.iam.v1.GetIamPolicyRequest;
 import com.google.iam.v1.Policy;
diff --git a/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/ConfigServiceV2StubSettings.java b/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/ConfigServiceV2StubSettings.java
index 8916f2ab8922..abe760a9a13d 100644
--- a/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/ConfigServiceV2StubSettings.java
+++ b/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/ConfigServiceV2StubSettings.java
@@ -280,7 +280,9 @@ public String extractNextToken(ListSinksResponse payload) {
 
             @Override
             public Iterable<LogSink> extractResources(ListSinksResponse payload) {
-              return payload.getSinksList();
+              return payload.getSinksList() != null
+                  ? payload.getSinksList()
+                  : ImmutableList.<LogSink>of();
             }
           };
 
@@ -316,7 +318,9 @@ public String extractNextToken(ListExclusionsResponse payload) {
 
             @Override
             public Iterable<LogExclusion> extractResources(ListExclusionsResponse payload) {
-              return payload.getExclusionsList();
+              return payload.getExclusionsList() != null
+                  ? payload.getExclusionsList()
+                  : ImmutableList.<LogExclusion>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/LoggingServiceV2StubSettings.java b/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/LoggingServiceV2StubSettings.java
index 097f634aba94..e1353f8a61e6 100644
--- a/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/LoggingServiceV2StubSettings.java
+++ b/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/LoggingServiceV2StubSettings.java
@@ -262,7 +262,9 @@ public String extractNextToken(ListLogEntriesResponse payload) {
 
             @Override
             public Iterable<LogEntry> extractResources(ListLogEntriesResponse payload) {
-              return payload.getEntriesList();
+              return payload.getEntriesList() != null
+                  ? payload.getEntriesList()
+                  : ImmutableList.<LogEntry>of();
             }
           };
 
@@ -307,7 +309,9 @@ public String extractNextToken(ListMonitoredResourceDescriptorsResponse payload)
             @Override
             public Iterable<MonitoredResourceDescriptor> extractResources(
                 ListMonitoredResourceDescriptorsResponse payload) {
-              return payload.getResourceDescriptorsList();
+              return payload.getResourceDescriptorsList() != null
+                  ? payload.getResourceDescriptorsList()
+                  : ImmutableList.<MonitoredResourceDescriptor>of();
             }
           };
 
@@ -341,7 +345,9 @@ public String extractNextToken(ListLogsResponse payload) {
 
             @Override
             public Iterable<String> extractResources(ListLogsResponse payload) {
-              return payload.getLogNamesList();
+              return payload.getLogNamesList() != null
+                  ? payload.getLogNamesList()
+                  : ImmutableList.<String>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/MetricsServiceV2StubSettings.java b/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/MetricsServiceV2StubSettings.java
index 6f62a06191f2..9a6af63de6bd 100644
--- a/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/MetricsServiceV2StubSettings.java
+++ b/google-cloud-clients/google-cloud-logging/src/main/java/com/google/cloud/logging/v2/stub/MetricsServiceV2StubSettings.java
@@ -236,7 +236,9 @@ public String extractNextToken(ListLogMetricsResponse payload) {
 
             @Override
             public Iterable<LogMetric> extractResources(ListLogMetricsResponse payload) {
-              return payload.getMetricsList();
+              return payload.getMetricsList() != null
+                  ? payload.getMetricsList()
+                  : ImmutableList.<LogMetric>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-redis/src/main/java/com/google/cloud/redis/v1/stub/CloudRedisStubSettings.java b/google-cloud-clients/google-cloud-redis/src/main/java/com/google/cloud/redis/v1/stub/CloudRedisStubSettings.java
index 0456e15fbf03..ee9d0576162f 100644
--- a/google-cloud-clients/google-cloud-redis/src/main/java/com/google/cloud/redis/v1/stub/CloudRedisStubSettings.java
+++ b/google-cloud-clients/google-cloud-redis/src/main/java/com/google/cloud/redis/v1/stub/CloudRedisStubSettings.java
@@ -264,7 +264,9 @@ public String extractNextToken(ListInstancesResponse payload) {
 
             @Override
             public Iterable<Instance> extractResources(ListInstancesResponse payload) {
-              return payload.getInstancesList();
+              return payload.getInstancesList() != null
+                  ? payload.getInstancesList()
+                  : ImmutableList.<Instance>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-redis/src/main/java/com/google/cloud/redis/v1beta1/stub/CloudRedisStubSettings.java b/google-cloud-clients/google-cloud-redis/src/main/java/com/google/cloud/redis/v1beta1/stub/CloudRedisStubSettings.java
index 9b7dffae786d..ab731babfad4 100644
--- a/google-cloud-clients/google-cloud-redis/src/main/java/com/google/cloud/redis/v1beta1/stub/CloudRedisStubSettings.java
+++ b/google-cloud-clients/google-cloud-redis/src/main/java/com/google/cloud/redis/v1beta1/stub/CloudRedisStubSettings.java
@@ -264,7 +264,9 @@ public String extractNextToken(ListInstancesResponse payload) {
 
             @Override
             public Iterable<Instance> extractResources(ListInstancesResponse payload) {
-              return payload.getInstancesList();
+              return payload.getInstancesList() != null
+                  ? payload.getInstancesList()
+                  : ImmutableList.<Instance>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-redis/src/test/java/com/google/cloud/redis/v1/CloudRedisClientTest.java b/google-cloud-clients/google-cloud-redis/src/test/java/com/google/cloud/redis/v1/CloudRedisClientTest.java
index 2975ba212f9f..3d61eb5467db 100644
--- a/google-cloud-clients/google-cloud-redis/src/test/java/com/google/cloud/redis/v1/CloudRedisClientTest.java
+++ b/google-cloud-clients/google-cloud-redis/src/test/java/com/google/cloud/redis/v1/CloudRedisClientTest.java
@@ -25,7 +25,6 @@
 import com.google.api.gax.rpc.ApiClientHeaderProvider;
 import com.google.api.gax.rpc.InvalidArgumentException;
 import com.google.api.gax.rpc.StatusCode;
-import com.google.cloud.redis.v1.Instance.Tier;
 import com.google.common.collect.Lists;
 import com.google.longrunning.Operation;
 import com.google.protobuf.Any;
diff --git a/google-cloud-clients/google-cloud-redis/src/test/java/com/google/cloud/redis/v1beta1/CloudRedisClientTest.java b/google-cloud-clients/google-cloud-redis/src/test/java/com/google/cloud/redis/v1beta1/CloudRedisClientTest.java
index 29c1bd58e2bb..9871362ea9fb 100644
--- a/google-cloud-clients/google-cloud-redis/src/test/java/com/google/cloud/redis/v1beta1/CloudRedisClientTest.java
+++ b/google-cloud-clients/google-cloud-redis/src/test/java/com/google/cloud/redis/v1beta1/CloudRedisClientTest.java
@@ -25,7 +25,6 @@
 import com.google.api.gax.rpc.ApiClientHeaderProvider;
 import com.google.api.gax.rpc.InvalidArgumentException;
 import com.google.api.gax.rpc.StatusCode;
-import com.google.cloud.redis.v1beta1.Instance.Tier;
 import com.google.common.collect.Lists;
 import com.google.longrunning.Operation;
 import com.google.protobuf.Any;
diff --git a/google-cloud-clients/google-cloud-scheduler/src/main/java/com/google/cloud/scheduler/v1beta1/stub/CloudSchedulerStubSettings.java b/google-cloud-clients/google-cloud-scheduler/src/main/java/com/google/cloud/scheduler/v1beta1/stub/CloudSchedulerStubSettings.java
index 99413454e524..7c4112eff81f 100644
--- a/google-cloud-clients/google-cloud-scheduler/src/main/java/com/google/cloud/scheduler/v1beta1/stub/CloudSchedulerStubSettings.java
+++ b/google-cloud-clients/google-cloud-scheduler/src/main/java/com/google/cloud/scheduler/v1beta1/stub/CloudSchedulerStubSettings.java
@@ -252,7 +252,9 @@ public String extractNextToken(ListJobsResponse payload) {
 
             @Override
             public Iterable<Job> extractResources(ListJobsResponse payload) {
-              return payload.getJobsList();
+              return payload.getJobsList() != null
+                  ? payload.getJobsList()
+                  : ImmutableList.<Job>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-securitycenter/src/main/java/com/google/cloud/securitycenter/v1beta1/SecurityCenterClient.java b/google-cloud-clients/google-cloud-securitycenter/src/main/java/com/google/cloud/securitycenter/v1beta1/SecurityCenterClient.java
index 330c93f91bd4..69a1e7e78037 100644
--- a/google-cloud-clients/google-cloud-securitycenter/src/main/java/com/google/cloud/securitycenter/v1beta1/SecurityCenterClient.java
+++ b/google-cloud-clients/google-cloud-securitycenter/src/main/java/com/google/cloud/securitycenter/v1beta1/SecurityCenterClient.java
@@ -27,7 +27,6 @@
 import com.google.api.gax.rpc.OperationCallable;
 import com.google.api.gax.rpc.PageContext;
 import com.google.api.gax.rpc.UnaryCallable;
-import com.google.cloud.securitycenter.v1beta1.Finding.State;
 import com.google.cloud.securitycenter.v1beta1.ListAssetsResponse.ListAssetsResult;
 import com.google.cloud.securitycenter.v1beta1.stub.SecurityCenterStub;
 import com.google.cloud.securitycenter.v1beta1.stub.SecurityCenterStubSettings;
diff --git a/google-cloud-clients/google-cloud-securitycenter/src/main/java/com/google/cloud/securitycenter/v1beta1/stub/SecurityCenterStubSettings.java b/google-cloud-clients/google-cloud-securitycenter/src/main/java/com/google/cloud/securitycenter/v1beta1/stub/SecurityCenterStubSettings.java
index 40b734310c72..3e7a4641f0ca 100644
--- a/google-cloud-clients/google-cloud-securitycenter/src/main/java/com/google/cloud/securitycenter/v1beta1/stub/SecurityCenterStubSettings.java
+++ b/google-cloud-clients/google-cloud-securitycenter/src/main/java/com/google/cloud/securitycenter/v1beta1/stub/SecurityCenterStubSettings.java
@@ -382,7 +382,9 @@ public String extractNextToken(GroupAssetsResponse payload) {
 
             @Override
             public Iterable<GroupResult> extractResources(GroupAssetsResponse payload) {
-              return payload.getGroupByResultsList();
+              return payload.getGroupByResultsList() != null
+                  ? payload.getGroupByResultsList()
+                  : ImmutableList.<GroupResult>of();
             }
           };
 
@@ -416,7 +418,9 @@ public String extractNextToken(GroupFindingsResponse payload) {
 
             @Override
             public Iterable<GroupResult> extractResources(GroupFindingsResponse payload) {
-              return payload.getGroupByResultsList();
+              return payload.getGroupByResultsList() != null
+                  ? payload.getGroupByResultsList()
+                  : ImmutableList.<GroupResult>of();
             }
           };
 
@@ -453,7 +457,9 @@ public String extractNextToken(ListAssetsResponse payload) {
             @Override
             public Iterable<ListAssetsResponse.ListAssetsResult> extractResources(
                 ListAssetsResponse payload) {
-              return payload.getListAssetsResultsList();
+              return payload.getListAssetsResultsList() != null
+                  ? payload.getListAssetsResultsList()
+                  : ImmutableList.<ListAssetsResponse.ListAssetsResult>of();
             }
           };
 
@@ -487,7 +493,9 @@ public String extractNextToken(ListFindingsResponse payload) {
 
             @Override
             public Iterable<Finding> extractResources(ListFindingsResponse payload) {
-              return payload.getFindingsList();
+              return payload.getFindingsList() != null
+                  ? payload.getFindingsList()
+                  : ImmutableList.<Finding>of();
             }
           };
 
@@ -521,7 +529,9 @@ public String extractNextToken(ListSourcesResponse payload) {
 
             @Override
             public Iterable<Source> extractResources(ListSourcesResponse payload) {
-              return payload.getSourcesList();
+              return payload.getSourcesList() != null
+                  ? payload.getSourcesList()
+                  : ImmutableList.<Source>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-securitycenter/src/test/java/com/google/cloud/securitycenter/v1beta1/SecurityCenterClientTest.java b/google-cloud-clients/google-cloud-securitycenter/src/test/java/com/google/cloud/securitycenter/v1beta1/SecurityCenterClientTest.java
index cd1c1c9856b1..4322a27d5b30 100644
--- a/google-cloud-clients/google-cloud-securitycenter/src/test/java/com/google/cloud/securitycenter/v1beta1/SecurityCenterClientTest.java
+++ b/google-cloud-clients/google-cloud-securitycenter/src/test/java/com/google/cloud/securitycenter/v1beta1/SecurityCenterClientTest.java
@@ -26,7 +26,6 @@
 import com.google.api.gax.rpc.ApiClientHeaderProvider;
 import com.google.api.gax.rpc.InvalidArgumentException;
 import com.google.api.gax.rpc.StatusCode;
-import com.google.cloud.securitycenter.v1beta1.Finding.State;
 import com.google.common.collect.Lists;
 import com.google.iam.v1.GetIamPolicyRequest;
 import com.google.iam.v1.Policy;
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/database/v1/stub/DatabaseAdminStubSettings.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/database/v1/stub/DatabaseAdminStubSettings.java
index b0bac76fc0a1..0b131a4a3e5a 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/database/v1/stub/DatabaseAdminStubSettings.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/database/v1/stub/DatabaseAdminStubSettings.java
@@ -297,7 +297,9 @@ public String extractNextToken(ListDatabasesResponse payload) {
 
             @Override
             public Iterable<Database> extractResources(ListDatabasesResponse payload) {
-              return payload.getDatabasesList();
+              return payload.getDatabasesList() != null
+                  ? payload.getDatabasesList()
+                  : ImmutableList.<Database>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/instance/v1/stub/InstanceAdminStubSettings.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/instance/v1/stub/InstanceAdminStubSettings.java
index 7a33417a3bdb..7aa44918a333 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/instance/v1/stub/InstanceAdminStubSettings.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/admin/instance/v1/stub/InstanceAdminStubSettings.java
@@ -314,7 +314,9 @@ public String extractNextToken(ListInstanceConfigsResponse payload) {
 
             @Override
             public Iterable<InstanceConfig> extractResources(ListInstanceConfigsResponse payload) {
-              return payload.getInstanceConfigsList();
+              return payload.getInstanceConfigsList() != null
+                  ? payload.getInstanceConfigsList()
+                  : ImmutableList.<InstanceConfig>of();
             }
           };
 
@@ -348,7 +350,9 @@ public String extractNextToken(ListInstancesResponse payload) {
 
             @Override
             public Iterable<Instance> extractResources(ListInstancesResponse payload) {
-              return payload.getInstancesList();
+              return payload.getInstancesList() != null
+                  ? payload.getInstancesList()
+                  : ImmutableList.<Instance>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/v1/stub/SpannerStubSettings.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/v1/stub/SpannerStubSettings.java
index 6cf3c210e11f..f9d42de35cfd 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/v1/stub/SpannerStubSettings.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/v1/stub/SpannerStubSettings.java
@@ -300,7 +300,9 @@ public String extractNextToken(ListSessionsResponse payload) {
 
             @Override
             public Iterable<Session> extractResources(ListSessionsResponse payload) {
-              return payload.getSessionsList();
+              return payload.getSessionsList() != null
+                  ? payload.getSessionsList()
+                  : ImmutableList.<Session>of();
             }
           };
 
@@ -380,6 +382,17 @@ public static class Builder extends StubSettings.Builder<SpannerStubSettings, Bu
               .setTotalTimeout(Duration.ofMillis(600000L))
               .build();
       definitions.put("default", settings);
+      settings =
+          RetrySettings.newBuilder()
+              .setInitialRetryDelay(Duration.ofMillis(1000L))
+              .setRetryDelayMultiplier(1.3)
+              .setMaxRetryDelay(Duration.ofMillis(32000L))
+              .setInitialRpcTimeout(Duration.ofMillis(120000L))
+              .setRpcTimeoutMultiplier(1.0)
+              .setMaxRpcTimeout(Duration.ofMillis(120000L))
+              .setTotalTimeout(Duration.ofMillis(1200000L))
+              .build();
+      definitions.put("streaming", settings);
       settings =
           RetrySettings.newBuilder()
               .setInitialRetryDelay(Duration.ofMillis(1000L))
@@ -483,7 +496,7 @@ private static Builder initDefaults(Builder builder) {
       builder
           .executeStreamingSqlSettings()
           .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("non_idempotent"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("default"));
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("streaming"));
 
       builder
           .readSettings()
@@ -493,7 +506,7 @@ private static Builder initDefaults(Builder builder) {
       builder
           .streamingReadSettings()
           .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("non_idempotent"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("default"));
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("streaming"));
 
       builder
           .beginTransactionSettings()
diff --git a/google-cloud-clients/google-cloud-tasks/src/main/java/com/google/cloud/tasks/v2beta2/stub/CloudTasksStubSettings.java b/google-cloud-clients/google-cloud-tasks/src/main/java/com/google/cloud/tasks/v2beta2/stub/CloudTasksStubSettings.java
index 2889d1f92704..920bd9c4c6a7 100644
--- a/google-cloud-clients/google-cloud-tasks/src/main/java/com/google/cloud/tasks/v2beta2/stub/CloudTasksStubSettings.java
+++ b/google-cloud-clients/google-cloud-tasks/src/main/java/com/google/cloud/tasks/v2beta2/stub/CloudTasksStubSettings.java
@@ -357,7 +357,9 @@ public String extractNextToken(ListQueuesResponse payload) {
 
             @Override
             public Iterable<Queue> extractResources(ListQueuesResponse payload) {
-              return payload.getQueuesList();
+              return payload.getQueuesList() != null
+                  ? payload.getQueuesList()
+                  : ImmutableList.<Queue>of();
             }
           };
 
@@ -391,7 +393,9 @@ public String extractNextToken(ListTasksResponse payload) {
 
             @Override
             public Iterable<Task> extractResources(ListTasksResponse payload) {
-              return payload.getTasksList();
+              return payload.getTasksList() != null
+                  ? payload.getTasksList()
+                  : ImmutableList.<Task>of();
             }
           };
 
diff --git a/google-cloud-clients/google-cloud-tasks/src/main/java/com/google/cloud/tasks/v2beta3/stub/CloudTasksStubSettings.java b/google-cloud-clients/google-cloud-tasks/src/main/java/com/google/cloud/tasks/v2beta3/stub/CloudTasksStubSettings.java
index fcf4f0eaa744..0f666bcb7f42 100644
--- a/google-cloud-clients/google-cloud-tasks/src/main/java/com/google/cloud/tasks/v2beta3/stub/CloudTasksStubSettings.java
+++ b/google-cloud-clients/google-cloud-tasks/src/main/java/com/google/cloud/tasks/v2beta3/stub/CloudTasksStubSettings.java
@@ -324,7 +324,9 @@ public String extractNextToken(ListQueuesResponse payload) {
 
             @Override
             public Iterable<Queue> extractResources(ListQueuesResponse payload) {
-              return payload.getQueuesList();
+              return payload.getQueuesList() != null
+                  ? payload.getQueuesList()
+                  : ImmutableList.<Queue>of();
             }
           };
 
@@ -358,7 +360,9 @@ public String extractNextToken(ListTasksResponse payload) {
 
             @Override
             public Iterable<Task> extractResources(ListTasksResponse payload) {
-              return payload.getTasksList();
+              return payload.getTasksList() != null
+                  ? payload.getTasksList()
+                  : ImmutableList.<Task>of();
             }
           };