Bigtable: add enhanced stub for bigtable table admin client

This will be used googleapis#3658 to add new callables that can't be autogenerated.

Author: igorbernstein2

google-cloud-clients/google-cloud-bigtable-admin/src/main/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminClient.java

@@ -34,7 +34,7 @@
 import com.google.cloud.bigtable.admin.v2.models.CreateTableRequest;
 import com.google.cloud.bigtable.admin.v2.models.ModifyColumnFamiliesRequest;
 import com.google.cloud.bigtable.admin.v2.models.Table;
-import com.google.cloud.bigtable.admin.v2.stub.BigtableTableAdminStub;
+import com.google.cloud.bigtable.admin.v2.stub.EnhancedBigtableTableAdminStub;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
@@ -97,7 +97,7 @@
  * }</pre>
  */
 public final class BigtableTableAdminClient implements AutoCloseable {
-  private final BigtableTableAdminStub stub;
+  private final EnhancedBigtableTableAdminStub stub;
   private final InstanceName instanceName;
 
   /** Constructs an instance of BigtableTableAdminClient with the given instanceName. */
@@ -109,17 +109,19 @@ public static BigtableTableAdminClient create(@Nonnull InstanceName instanceName
   /** Constructs an instance of BigtableTableAdminClient with the given settings. */
   public static BigtableTableAdminClient create(@Nonnull BigtableTableAdminSettings settings)
       throws IOException {
-    return create(settings.getInstanceName(), settings.getStubSettings().createStub());
+    EnhancedBigtableTableAdminStub stub = EnhancedBigtableTableAdminStub
+        .createEnhanced(settings.getStubSettings());
+    return create(settings.getInstanceName(), stub);
   }
 
   /** Constructs an instance of BigtableTableAdminClient with the given instanceName and stub. */
   public static BigtableTableAdminClient create(@Nonnull InstanceName instanceName,
-      @Nonnull BigtableTableAdminStub stub) {
+      @Nonnull EnhancedBigtableTableAdminStub stub) {
     return new BigtableTableAdminClient(instanceName, stub);
   }
 
   private BigtableTableAdminClient(@Nonnull InstanceName instanceName,
-      @Nonnull BigtableTableAdminStub stub) {
+      @Nonnull EnhancedBigtableTableAdminStub stub) {
     Preconditions.checkNotNull(instanceName);
     Preconditions.checkNotNull(stub);
     this.instanceName = instanceName;

google-cloud-clients/google-cloud-bigtable-admin/src/main/java/com/google/cloud/bigtable/admin/v2/stub/EnhancedBigtableTableAdminStub.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2018 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.cloud.bigtable.admin.v2.stub;
+
+import com.google.api.core.InternalApi;
+import com.google.api.gax.retrying.RetrySettings;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.bigtable.admin.v2.TableName;
+import java.io.IOException;
+import org.threeten.bp.Duration;
+
+/**
+ * Extension of the autogenerated {@link GrpcBigtableTableAdminStub}. It acts as a decorator to add
+ * enhanced abilities to the autogenerated stub.
+ *
+ * <p>This class is considered an internal implementation detail and not meant to be used by
+ * applications.
+ */
+@InternalApi
+public class EnhancedBigtableTableAdminStub extends GrpcBigtableTableAdminStub {
+  private final BigtableTableAdminStubSettings settings;
+  private final ClientContext clientContext;
+
+  public static EnhancedBigtableTableAdminStub createEnhanced(
+      BigtableTableAdminStubSettings settings)
+      throws IOException {
+
+    return new EnhancedBigtableTableAdminStub(settings, ClientContext.create(settings));
+  }
+
+  private EnhancedBigtableTableAdminStub(BigtableTableAdminStubSettings settings,
+      ClientContext clientContext) throws IOException {
+    super(settings, clientContext);
+
+    this.settings = settings;
+    this.clientContext = clientContext;
+  }
+}

google-cloud-clients/google-cloud-bigtable-admin/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminClientTest.java

@@ -40,6 +40,7 @@
 import com.google.cloud.bigtable.admin.v2.models.ModifyColumnFamiliesRequest;
 import com.google.cloud.bigtable.admin.v2.models.Table;
 import com.google.cloud.bigtable.admin.v2.stub.BigtableTableAdminStub;
+import com.google.cloud.bigtable.admin.v2.stub.EnhancedBigtableTableAdminStub;
 import com.google.common.collect.Lists;
 import com.google.protobuf.ByteString;
 import com.google.protobuf.Empty;
@@ -63,7 +64,7 @@ public class BigtableTableAdminClientTest {
 
   private BigtableTableAdminClient adminClient;
   @Mock
-  private BigtableTableAdminStub mockStub;
+  private EnhancedBigtableTableAdminStub mockStub;
 
   @Mock
   private UnaryCallable<com.google.bigtable.admin.v2.CreateTableRequest, com.google.bigtable.admin.v2.Table> mockCreateTableCallable;