Add comments to add back abstract keyword on the methods used to be a…

…bstract

Signed-off-by: Tianli Feng <[email protected]>

server/src/main/java/org/opensearch/action/support/clustermanager/TransportClusterManagerNodeAction.java

@@ -125,6 +125,7 @@ protected void masterOperation(Request request, ClusterState state, ActionListen
         throw new UnsupportedOperationException("Must be overridden");
     }
 
+    // TODO: Add abstract keyword after removing the deprecated masterOperation()
     protected void clusterManagerOperation(Request request, ClusterState state, ActionListener<Response> listener) throws Exception {
         masterOperation(request, state, listener);
     }

server/src/main/java/org/opensearch/action/support/clustermanager/info/TransportClusterInfoAction.java

@@ -88,6 +88,7 @@ protected final void clusterManagerOperation(final Request request, final Cluste
         doClusterManagerOperation(request, concreteIndices, state, listener);
     }
 
+    // TODO: Add abstract keyword after removing the deprecated doMasterOperation()
     protected void doClusterManagerOperation(
         Request request,
         String[] concreteIndices,

test/framework/src/main/java/org/opensearch/test/TestCluster.java

@@ -127,6 +127,7 @@ public void assertAfterTest() throws Exception {
     /**
      * Returns the number of data and cluster-manager eligible nodes in the cluster.
      */
+    // TODO: Add abstract keyword after removing the deprecated numDataAndMasterNodes()
     public int numDataAndClusterManagerNodes() {
         return numDataAndMasterNodes();
     }