[PURIFY] remove all trace of x-pack graph (#13)

This commit removes all trace of Elastic licensed graph feature

buildSrc/src/main/resources/checkstyle_suppressions.xml

@@ -29,7 +29,6 @@
     documentation that are so wide that they scroll.
   -->
   <suppress files="client[/\\]rest-high-level[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]client[/\\]documentation[/\\]ClusterClientDocumentationIT.java" id="SnippetLength" />
-  <suppress files="client[/\\]rest-high-level[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]client[/\\]documentation[/\\]GraphDocumentationIT.java" id="SnippetLength" />
   <suppress files="client[/\\]rest-high-level[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]client[/\\]documentation[/\\]CRUDDocumentationIT.java" id="SnippetLength" />
   <suppress files="client[/\\]rest-high-level[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]client[/\\]documentation[/\\]IndicesClientDocumentationIT.java" id="SnippetLength" />
   <suppress files="client[/\\]rest-high-level[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]client[/\\]documentation[/\\]IngestClientDocumentationIT.java" id="SnippetLength" />

client/rest-high-level/src/main/java/org/elasticsearch/client/RestHighLevelClient.java

@@ -261,7 +261,6 @@ public class RestHighLevelClient implements Closeable {
     private final SnapshotClient snapshotClient = new SnapshotClient(this);
     private final TasksClient tasksClient = new TasksClient(this);
     private final WatcherClient watcherClient = new WatcherClient(this);
-    private final GraphClient graphClient = new GraphClient(this);
     private final MigrationClient migrationClient = new MigrationClient(this);
     private final MachineLearningClient machineLearningClient = new MachineLearningClient(this);
     private final SecurityClient securityClient = new SecurityClient(this);
@@ -380,16 +379,6 @@ public final TasksClient tasks() {
      */
     public WatcherClient watcher() { return watcherClient; }
 
-    /**
-     * Provides methods for accessing the Elastic Licensed Graph explore API that
-     * is shipped with the default distribution of Elasticsearch. All of
-     * these APIs will 404 if run against the OSS distribution of Elasticsearch.
-     * <p>
-     * See the <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/graph-explore-api.html">
-     * Graph API on elastic.co</a> for more information.
-     */
-    public GraphClient graph() { return graphClient; }
-
     /**
      * A wrapper for the {@link RestHighLevelClient} that provides methods for
      * accessing the Elastic Index Lifecycle APIs.