}
    }

    /**
     * Performs witness registration.
     *
     * @param request the registration request
     * @return the registration response
     * @throws IOException if the RPC call fails
     */
    public WitnessRegisterResponse register(WitnessRegisterRequest request) throws IOException {
        if (!connected) {
            throw new IOException("Witness client not connected");
        }

          executorService.submit(
              new Callable<@Nullable Void>() {
                @Override
                public @Nullable Void call() throws Exception {
                  startLatch.countDown();
                  startLatch.await();
                  callable.call();
                  doneLatch.countDown();
                  return null;
                }
              });
    }
    doneLatch.await();

 * .compare(a.foo, b.bar)}. {@code ComparisonChain} also has a potential performance problem that
 * {@code Comparator} doesn't: it evaluates all the parameters of all the {@code .compare} calls,
 * even when the result of the comparison is already known from previous {@code .compare} calls.
 * That can be expensive.
 *
 * @author Mark Davis
 * @author Kevin Bourrillion
 * @since 2.0
 */
@GwtCompatible
public abstract class ComparisonChain {

   * <p>This method is {@code protected} so that classes like {@code
   * com.google.common.util.concurrent.SettableFuture} do not expose it to their users as an
   * instance method. In the unlikely event that you need to call this method, call {@link
   * InternalFutures#tryInternalFastPathGetFailure(InternalFutureFailureAccess)}.
   */
  protected abstract
      Throwable
      tryInternalFastPathGetFailure();

    return incidentEdges();
  }

  @Override
  public Set<E> outEdges() {
    return incidentEdges();
  }

  @Override
  public N adjacentNode(E edge) {
    // We're relying on callers to call this method only with an edge that's in the graph.
    return requireNonNull(incidentEdgeMap.get(edge));
  }

  @Override
  public @Nullable N removeInEdge(E edge, boolean isSelfLoop) {
    if (!isSelfLoop) {

@NullUnmarked
public class ListenerCallQueueTest extends TestCase {

  private static final ListenerCallQueue.Event<Object> THROWING_EVENT =
      new ListenerCallQueue.Event<Object>() {
        @Override
        public void call(Object object) {
          throw new RuntimeException();
        }

        @Override
        public String toString() {
          return "throwing()";
        }
      };

@NullUnmarked
public class ListenerCallQueueTest extends TestCase {

  private static final ListenerCallQueue.Event<Object> THROWING_EVENT =
      new ListenerCallQueue.Event<Object>() {
        @Override
        public void call(Object object) {
          throw new RuntimeException();
        }

        @Override
        public String toString() {
          return "throwing()";
        }
      };

    if (subjectGenerator == null) {
      throw new IllegalStateException("Call using() before createTestSuite().");
    }
    if (name == null) {
      throw new IllegalStateException("Call named() before createTestSuite().");
    }
    if (features == null) {
      throw new IllegalStateException("Call withFeatures() before createTestSuite().");
    }
  }

	return opts, nil
}

// get ObjectOptions for Copy calls with encryption headers provided on the target side and source side metadata
func copyDstOpts(ctx context.Context, r *http.Request, bucket, object string, metadata map[string]string) (opts ObjectOptions, err error) {
	return putOptsFromReq(ctx, r, bucket, object, metadata)
}

// get ObjectOptions for Copy calls with encryption headers provided on the source side

       * column, the rows in the second column, etc.
       */
      Comparator<Cell<R, C, V>> comparator =
          (Cell<R, C, V> cell1, Cell<R, C, V> cell2) -> {
            int rowCompare =
                (rowComparator == null)
                    ? 0
                    : rowComparator.compare(cell1.getRowKey(), cell2.getRowKey());
            if (rowCompare != 0) {
              return rowCompare;
            }