BaseBigQueryReadClient.java

/*
 * Copyright 2023 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.bigquery.storage.v1;

import com.google.api.gax.core.BackgroundResource;
import com.google.api.gax.rpc.ServerStreamingCallable;
import com.google.api.gax.rpc.UnaryCallable;
import com.google.cloud.bigquery.storage.v1.stub.BigQueryReadStub;
import com.google.cloud.bigquery.storage.v1.stub.BigQueryReadStubSettings;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import javax.annotation.Generated;

// AUTO-GENERATED DOCUMENTATION AND CLASS.
/**
 * Service Description: BigQuery Read API.
 *
 * <p>The Read API can be used to read data from BigQuery.
 *
 * <p>This class provides the ability to make remote calls to the backing service through method
 * calls that map to API methods. Sample code to get started:
 *
 * <pre>{@code
 * // This snippet has been automatically generated and should be regarded as a code template only.
 * // It will require modifications to work:
 * // - It may require correct/in-range values for request initialization.
 * // - It may require specifying regional endpoints when creating the service client as shown in
 * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 * try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
 *   ProjectName parent = ProjectName.of("[PROJECT]");
 *   ReadSession readSession = ReadSession.newBuilder().build();
 *   int maxStreamCount = 940837515;
 *   ReadSession response =
 *       baseBigQueryReadClient.createReadSession(parent, readSession, maxStreamCount);
 * }
 * }</pre>
 *
 * <p>Note: close() needs to be called on the BaseBigQueryReadClient object to clean up resources
 * such as threads. In the example above, try-with-resources is used, which automatically calls
 * close().
 *
 * <table>
 *    <caption>Methods</caption>
 *    <tr>
 *      <th>Method</th>
 *      <th>Description</th>
 *      <th>Method Variants</th>
 *    </tr>
 *    <tr>
 *      <td><p> CreateReadSession</td>
 *      <td><p> Creates a new read session. A read session divides the contents of a BigQuery table into one or more streams, which can then be used to read data from the table. The read session also specifies properties of the data to be read, such as a list of columns or a push-down filter describing the rows to be returned.
 * <p>  A particular row can be read by at most one stream. When the caller has reached the end of each stream in the session, then all the data in the table has been read.
 * <p>  Data is assigned to each stream such that roughly the same number of rows can be read from each stream. Because the server-side unit for assigning data is collections of rows, the API does not guarantee that each stream will return the same number or rows. Additionally, the limits are enforced based on the number of pre-filtered rows, so some filters can lead to lopsided assignments.
 * <p>  Read sessions automatically expire 6 hours after they are created and do not require manual clean-up by the caller.</td>
 *      <td>
 *      <p>Request object method variants only take one parameter, a request object, which must be constructed before the call.</p>
 *      <ul>
 *           <li><p> createReadSession(CreateReadSessionRequest request)
 *      </ul>
 *      <p>"Flattened" method variants have converted the fields of the request object into function parameters to enable multiple ways to call the same method.</p>
 *      <ul>
 *           <li><p> createReadSession(ProjectName parent, ReadSession readSession, int maxStreamCount)
 *           <li><p> createReadSession(String parent, ReadSession readSession, int maxStreamCount)
 *      </ul>
 *      <p>Callable method variants take no parameters and return an immutable API callable object, which can be used to initiate calls to the service.</p>
 *      <ul>
 *           <li><p> createReadSessionCallable()
 *      </ul>
 *       </td>
 *    </tr>
 *    <tr>
 *      <td><p> ReadRows</td>
 *      <td><p> Reads rows from the stream in the format prescribed by the ReadSession. Each response contains one or more table rows, up to a maximum of 100 MiB per response; read requests which attempt to read individual rows larger than 100 MiB will fail.
 * <p>  Each request also returns a set of stream statistics reflecting the current state of the stream.</td>
 *      <td>
 *      <p>Callable method variants take no parameters and return an immutable API callable object, which can be used to initiate calls to the service.</p>
 *      <ul>
 *           <li><p> readRowsCallable()
 *      </ul>
 *       </td>
 *    </tr>
 *    <tr>
 *      <td><p> SplitReadStream</td>
 *      <td><p> Splits a given `ReadStream` into two `ReadStream` objects. These `ReadStream` objects are referred to as the primary and the residual streams of the split. The original `ReadStream` can still be read from in the same manner as before. Both of the returned `ReadStream` objects can also be read from, and the rows returned by both child streams will be the same as the rows read from the original stream.
 * <p>  Moreover, the two child streams will be allocated back-to-back in the original `ReadStream`. Concretely, it is guaranteed that for streams original, primary, and residual, that original[0-j] = primary[0-j] and original[j-n] = residual[0-m] once the streams have been read to completion.</td>
 *      <td>
 *      <p>Request object method variants only take one parameter, a request object, which must be constructed before the call.</p>
 *      <ul>
 *           <li><p> splitReadStream(SplitReadStreamRequest request)
 *      </ul>
 *      <p>Callable method variants take no parameters and return an immutable API callable object, which can be used to initiate calls to the service.</p>
 *      <ul>
 *           <li><p> splitReadStreamCallable()
 *      </ul>
 *       </td>
 *    </tr>
 *  </table>
 *
 * <p>See the individual methods for example code.
 *
 * <p>Many parameters require resource names to be formatted in a particular way. To assist with
 * these names, this class includes a format method for each type of name, and additionally a parse
 * method to extract the individual identifiers contained within names that are returned.
 *
 * <p>This class can be customized by passing in a custom instance of BaseBigQueryReadSettings to
 * create(). For example:
 *
 * <p>To customize credentials:
 *
 * <pre>{@code
 * // This snippet has been automatically generated and should be regarded as a code template only.
 * // It will require modifications to work:
 * // - It may require correct/in-range values for request initialization.
 * // - It may require specifying regional endpoints when creating the service client as shown in
 * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 * BaseBigQueryReadSettings baseBigQueryReadSettings =
 *     BaseBigQueryReadSettings.newBuilder()
 *         .setCredentialsProvider(FixedCredentialsProvider.create(myCredentials))
 *         .build();
 * BaseBigQueryReadClient baseBigQueryReadClient =
 *     BaseBigQueryReadClient.create(baseBigQueryReadSettings);
 * }</pre>
 *
 * <p>To customize the endpoint:
 *
 * <pre>{@code
 * // This snippet has been automatically generated and should be regarded as a code template only.
 * // It will require modifications to work:
 * // - It may require correct/in-range values for request initialization.
 * // - It may require specifying regional endpoints when creating the service client as shown in
 * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
 * BaseBigQueryReadSettings baseBigQueryReadSettings =
 *     BaseBigQueryReadSettings.newBuilder().setEndpoint(myEndpoint).build();
 * BaseBigQueryReadClient baseBigQueryReadClient =
 *     BaseBigQueryReadClient.create(baseBigQueryReadSettings);
 * }</pre>
 *
 * <p>Please refer to the GitHub repository's samples for more quickstart code snippets.
 */
@Generated("by gapic-generator-java")
public class BaseBigQueryReadClient implements BackgroundResource {
  private final BaseBigQueryReadSettings settings;
  private final BigQueryReadStub stub;

  /** Constructs an instance of BaseBigQueryReadClient with default settings. */
  public static final BaseBigQueryReadClient create() throws IOException {
    return create(BaseBigQueryReadSettings.newBuilder().build());
  }

  /**
   * Constructs an instance of BaseBigQueryReadClient, using the given settings. The channels are
   * created based on the settings passed in, or defaults for any settings that are not set.
   */
  public static final BaseBigQueryReadClient create(BaseBigQueryReadSettings settings)
      throws IOException {
    return new BaseBigQueryReadClient(settings);
  }

  /**
   * Constructs an instance of BaseBigQueryReadClient, using the given stub for making calls. This
   * is for advanced usage - prefer using create(BaseBigQueryReadSettings).
   */
  public static final BaseBigQueryReadClient create(BigQueryReadStub stub) {
    return new BaseBigQueryReadClient(stub);
  }

  /**
   * Constructs an instance of BaseBigQueryReadClient, using the given settings. This is protected
   * so that it is easy to make a subclass, but otherwise, the static factory methods should be
   * preferred.
   */
  protected BaseBigQueryReadClient(BaseBigQueryReadSettings settings) throws IOException {
    this.settings = settings;
    this.stub = ((BigQueryReadStubSettings) settings.getStubSettings()).createStub();
  }

  protected BaseBigQueryReadClient(BigQueryReadStub stub) {
    this.settings = null;
    this.stub = stub;
  }

  public final BaseBigQueryReadSettings getSettings() {
    return settings;
  }

  public BigQueryReadStub getStub() {
    return stub;
  }

  // AUTO-GENERATED DOCUMENTATION AND METHOD.
  /**
   * Creates a new read session. A read session divides the contents of a BigQuery table into one or
   * more streams, which can then be used to read data from the table. The read session also
   * specifies properties of the data to be read, such as a list of columns or a push-down filter
   * describing the rows to be returned.
   *
   * <p>A particular row can be read by at most one stream. When the caller has reached the end of
   * each stream in the session, then all the data in the table has been read.
   *
   * <p>Data is assigned to each stream such that roughly the same number of rows can be read from
   * each stream. Because the server-side unit for assigning data is collections of rows, the API
   * does not guarantee that each stream will return the same number or rows. Additionally, the
   * limits are enforced based on the number of pre-filtered rows, so some filters can lead to
   * lopsided assignments.
   *
   * <p>Read sessions automatically expire 6 hours after they are created and do not require manual
   * clean-up by the caller.
   *
   * <p>Sample code:
   *
   * <pre>{@code
   * // This snippet has been automatically generated and should be regarded as a code template only.
   * // It will require modifications to work:
   * // - It may require correct/in-range values for request initialization.
   * // - It may require specifying regional endpoints when creating the service client as shown in
   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
   * try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   *   ProjectName parent = ProjectName.of("[PROJECT]");
   *   ReadSession readSession = ReadSession.newBuilder().build();
   *   int maxStreamCount = 940837515;
   *   ReadSession response =
   *       baseBigQueryReadClient.createReadSession(parent, readSession, maxStreamCount);
   * }
   * }</pre>
   *
   * @param parent Required. The request project that owns the session, in the form of
   *     `projects/{project_id}`.
   * @param readSession Required. Session to be created.
   * @param maxStreamCount Max initial number of streams. If unset or zero, the server will provide
   *     a value of streams so as to produce reasonable throughput. Must be non-negative. The number
   *     of streams may be lower than the requested number, depending on the amount parallelism that
   *     is reasonable for the table. There is a default system max limit of 1,000.
   *     <p>This must be greater than or equal to preferred_min_stream_count. Typically, clients
   *     should either leave this unset to let the system to determine an upper bound OR set this a
   *     size for the maximum "units of work" it can gracefully handle.
   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
   */
  public final ReadSession createReadSession(
      ProjectName parent, ReadSession readSession, int maxStreamCount) {
    CreateReadSessionRequest request =
        CreateReadSessionRequest.newBuilder()
            .setParent(parent == null ? null : parent.toString())
            .setReadSession(readSession)
            .setMaxStreamCount(maxStreamCount)
            .build();
    return createReadSession(request);
  }

  // AUTO-GENERATED DOCUMENTATION AND METHOD.
  /**
   * Creates a new read session. A read session divides the contents of a BigQuery table into one or
   * more streams, which can then be used to read data from the table. The read session also
   * specifies properties of the data to be read, such as a list of columns or a push-down filter
   * describing the rows to be returned.
   *
   * <p>A particular row can be read by at most one stream. When the caller has reached the end of
   * each stream in the session, then all the data in the table has been read.
   *
   * <p>Data is assigned to each stream such that roughly the same number of rows can be read from
   * each stream. Because the server-side unit for assigning data is collections of rows, the API
   * does not guarantee that each stream will return the same number or rows. Additionally, the
   * limits are enforced based on the number of pre-filtered rows, so some filters can lead to
   * lopsided assignments.
   *
   * <p>Read sessions automatically expire 6 hours after they are created and do not require manual
   * clean-up by the caller.
   *
   * <p>Sample code:
   *
   * <pre>{@code
   * // This snippet has been automatically generated and should be regarded as a code template only.
   * // It will require modifications to work:
   * // - It may require correct/in-range values for request initialization.
   * // - It may require specifying regional endpoints when creating the service client as shown in
   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
   * try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   *   String parent = ProjectName.of("[PROJECT]").toString();
   *   ReadSession readSession = ReadSession.newBuilder().build();
   *   int maxStreamCount = 940837515;
   *   ReadSession response =
   *       baseBigQueryReadClient.createReadSession(parent, readSession, maxStreamCount);
   * }
   * }</pre>
   *
   * @param parent Required. The request project that owns the session, in the form of
   *     `projects/{project_id}`.
   * @param readSession Required. Session to be created.
   * @param maxStreamCount Max initial number of streams. If unset or zero, the server will provide
   *     a value of streams so as to produce reasonable throughput. Must be non-negative. The number
   *     of streams may be lower than the requested number, depending on the amount parallelism that
   *     is reasonable for the table. There is a default system max limit of 1,000.
   *     <p>This must be greater than or equal to preferred_min_stream_count. Typically, clients
   *     should either leave this unset to let the system to determine an upper bound OR set this a
   *     size for the maximum "units of work" it can gracefully handle.
   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
   */
  public final ReadSession createReadSession(
      String parent, ReadSession readSession, int maxStreamCount) {
    CreateReadSessionRequest request =
        CreateReadSessionRequest.newBuilder()
            .setParent(parent)
            .setReadSession(readSession)
            .setMaxStreamCount(maxStreamCount)
            .build();
    return createReadSession(request);
  }

  // AUTO-GENERATED DOCUMENTATION AND METHOD.
  /**
   * Creates a new read session. A read session divides the contents of a BigQuery table into one or
   * more streams, which can then be used to read data from the table. The read session also
   * specifies properties of the data to be read, such as a list of columns or a push-down filter
   * describing the rows to be returned.
   *
   * <p>A particular row can be read by at most one stream. When the caller has reached the end of
   * each stream in the session, then all the data in the table has been read.
   *
   * <p>Data is assigned to each stream such that roughly the same number of rows can be read from
   * each stream. Because the server-side unit for assigning data is collections of rows, the API
   * does not guarantee that each stream will return the same number or rows. Additionally, the
   * limits are enforced based on the number of pre-filtered rows, so some filters can lead to
   * lopsided assignments.
   *
   * <p>Read sessions automatically expire 6 hours after they are created and do not require manual
   * clean-up by the caller.
   *
   * <p>Sample code:
   *
   * <pre>{@code
   * // This snippet has been automatically generated and should be regarded as a code template only.
   * // It will require modifications to work:
   * // - It may require correct/in-range values for request initialization.
   * // - It may require specifying regional endpoints when creating the service client as shown in
   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
   * try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   *   CreateReadSessionRequest request =
   *       CreateReadSessionRequest.newBuilder()
   *           .setParent(ProjectName.of("[PROJECT]").toString())
   *           .setReadSession(ReadSession.newBuilder().build())
   *           .setMaxStreamCount(940837515)
   *           .setPreferredMinStreamCount(-1905507237)
   *           .build();
   *   ReadSession response = baseBigQueryReadClient.createReadSession(request);
   * }
   * }</pre>
   *
   * @param request The request object containing all of the parameters for the API call.
   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
   */
  public final ReadSession createReadSession(CreateReadSessionRequest request) {
    return createReadSessionCallable().call(request);
  }

  // AUTO-GENERATED DOCUMENTATION AND METHOD.
  /**
   * Creates a new read session. A read session divides the contents of a BigQuery table into one or
   * more streams, which can then be used to read data from the table. The read session also
   * specifies properties of the data to be read, such as a list of columns or a push-down filter
   * describing the rows to be returned.
   *
   * <p>A particular row can be read by at most one stream. When the caller has reached the end of
   * each stream in the session, then all the data in the table has been read.
   *
   * <p>Data is assigned to each stream such that roughly the same number of rows can be read from
   * each stream. Because the server-side unit for assigning data is collections of rows, the API
   * does not guarantee that each stream will return the same number or rows. Additionally, the
   * limits are enforced based on the number of pre-filtered rows, so some filters can lead to
   * lopsided assignments.
   *
   * <p>Read sessions automatically expire 6 hours after they are created and do not require manual
   * clean-up by the caller.
   *
   * <p>Sample code:
   *
   * <pre>{@code
   * // This snippet has been automatically generated and should be regarded as a code template only.
   * // It will require modifications to work:
   * // - It may require correct/in-range values for request initialization.
   * // - It may require specifying regional endpoints when creating the service client as shown in
   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
   * try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   *   CreateReadSessionRequest request =
   *       CreateReadSessionRequest.newBuilder()
   *           .setParent(ProjectName.of("[PROJECT]").toString())
   *           .setReadSession(ReadSession.newBuilder().build())
   *           .setMaxStreamCount(940837515)
   *           .setPreferredMinStreamCount(-1905507237)
   *           .build();
   *   ApiFuture<ReadSession> future =
   *       baseBigQueryReadClient.createReadSessionCallable().futureCall(request);
   *   // Do something.
   *   ReadSession response = future.get();
   * }
   * }</pre>
   */
  public final UnaryCallable<CreateReadSessionRequest, ReadSession> createReadSessionCallable() {
    return stub.createReadSessionCallable();
  }

  // AUTO-GENERATED DOCUMENTATION AND METHOD.
  /**
   * Reads rows from the stream in the format prescribed by the ReadSession. Each response contains
   * one or more table rows, up to a maximum of 100 MiB per response; read requests which attempt to
   * read individual rows larger than 100 MiB will fail.
   *
   * <p>Each request also returns a set of stream statistics reflecting the current state of the
   * stream.
   *
   * <p>Sample code:
   *
   * <pre>{@code
   * // This snippet has been automatically generated and should be regarded as a code template only.
   * // It will require modifications to work:
   * // - It may require correct/in-range values for request initialization.
   * // - It may require specifying regional endpoints when creating the service client as shown in
   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
   * try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   *   ReadRowsRequest request =
   *       ReadRowsRequest.newBuilder()
   *           .setReadStream(
   *               ReadStreamName.of("[PROJECT]", "[LOCATION]", "[SESSION]", "[STREAM]").toString())
   *           .setOffset(-1019779949)
   *           .build();
   *   ServerStream<ReadRowsResponse> stream =
   *       baseBigQueryReadClient.readRowsCallable().call(request);
   *   for (ReadRowsResponse response : stream) {
   *     // Do something when a response is received.
   *   }
   * }
   * }</pre>
   */
  public final ServerStreamingCallable<ReadRowsRequest, ReadRowsResponse> readRowsCallable() {
    return stub.readRowsCallable();
  }

  // AUTO-GENERATED DOCUMENTATION AND METHOD.
  /**
   * Splits a given `ReadStream` into two `ReadStream` objects. These `ReadStream` objects are
   * referred to as the primary and the residual streams of the split. The original `ReadStream` can
   * still be read from in the same manner as before. Both of the returned `ReadStream` objects can
   * also be read from, and the rows returned by both child streams will be the same as the rows
   * read from the original stream.
   *
   * <p>Moreover, the two child streams will be allocated back-to-back in the original `ReadStream`.
   * Concretely, it is guaranteed that for streams original, primary, and residual, that
   * original[0-j] = primary[0-j] and original[j-n] = residual[0-m] once the streams have been read
   * to completion.
   *
   * <p>Sample code:
   *
   * <pre>{@code
   * // This snippet has been automatically generated and should be regarded as a code template only.
   * // It will require modifications to work:
   * // - It may require correct/in-range values for request initialization.
   * // - It may require specifying regional endpoints when creating the service client as shown in
   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
   * try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   *   SplitReadStreamRequest request =
   *       SplitReadStreamRequest.newBuilder()
   *           .setName(
   *               ReadStreamName.of("[PROJECT]", "[LOCATION]", "[SESSION]", "[STREAM]").toString())
   *           .setFraction(-1653751294)
   *           .build();
   *   SplitReadStreamResponse response = baseBigQueryReadClient.splitReadStream(request);
   * }
   * }</pre>
   *
   * @param request The request object containing all of the parameters for the API call.
   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
   */
  public final SplitReadStreamResponse splitReadStream(SplitReadStreamRequest request) {
    return splitReadStreamCallable().call(request);
  }

  // AUTO-GENERATED DOCUMENTATION AND METHOD.
  /**
   * Splits a given `ReadStream` into two `ReadStream` objects. These `ReadStream` objects are
   * referred to as the primary and the residual streams of the split. The original `ReadStream` can
   * still be read from in the same manner as before. Both of the returned `ReadStream` objects can
   * also be read from, and the rows returned by both child streams will be the same as the rows
   * read from the original stream.
   *
   * <p>Moreover, the two child streams will be allocated back-to-back in the original `ReadStream`.
   * Concretely, it is guaranteed that for streams original, primary, and residual, that
   * original[0-j] = primary[0-j] and original[j-n] = residual[0-m] once the streams have been read
   * to completion.
   *
   * <p>Sample code:
   *
   * <pre>{@code
   * // This snippet has been automatically generated and should be regarded as a code template only.
   * // It will require modifications to work:
   * // - It may require correct/in-range values for request initialization.
   * // - It may require specifying regional endpoints when creating the service client as shown in
   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
   * try (BaseBigQueryReadClient baseBigQueryReadClient = BaseBigQueryReadClient.create()) {
   *   SplitReadStreamRequest request =
   *       SplitReadStreamRequest.newBuilder()
   *           .setName(
   *               ReadStreamName.of("[PROJECT]", "[LOCATION]", "[SESSION]", "[STREAM]").toString())
   *           .setFraction(-1653751294)
   *           .build();
   *   ApiFuture<SplitReadStreamResponse> future =
   *       baseBigQueryReadClient.splitReadStreamCallable().futureCall(request);
   *   // Do something.
   *   SplitReadStreamResponse response = future.get();
   * }
   * }</pre>
   */
  public final UnaryCallable<SplitReadStreamRequest, SplitReadStreamResponse>
      splitReadStreamCallable() {
    return stub.splitReadStreamCallable();
  }

  @Override
  public final void close() {
    stub.close();
  }

  @Override
  public void shutdown() {
    stub.shutdown();
  }

  @Override
  public boolean isShutdown() {
    return stub.isShutdown();
  }

  @Override
  public boolean isTerminated() {
    return stub.isTerminated();
  }

  @Override
  public void shutdownNow() {
    stub.shutdownNow();
  }

  @Override
  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
    return stub.awaitTermination(duration, unit);
  }
}