return 0;
    }
  }

  @Override
  public ListenableScheduledFuture<?> scheduleAtFixedRate(
      Runnable command, long initialDelay, long period, TimeUnit unit) {
    throw new UnsupportedOperationException("scheduleAtFixedRate is not supported.");
  }

  @Override
  public ListenableScheduledFuture<?> scheduleWithFixedDelay(

              @Override
              public ScheduledFuture<?> scheduleAtFixedRate(
                  Runnable command, long initialDelay, long period, TimeUnit unit) {
                assertSingleCallWithCorrectParameters(command, initialDelay, period, unit);
                return new ThrowingScheduledFuture<>();
              }
            },
            testRunnable);
    assertTrue(called);
  }

    // this will happen once the interrupt has been set which means that
    // 1. the runner has been woken up
    // 2. the interrupter is stuck in the call the Thread.interrupt()

    // after some period of time the runner thread should become blocked on the task because it is
    // waiting for the slow interrupting thread to complete Thread.interrupt
    awaitBlockedOnInstanceOf(runner, InterruptibleTask.Blocker.class);

              @Override
              public ScheduledFuture<?> scheduleAtFixedRate(
                  Runnable command, long initialDelay, long period, TimeUnit unit) {
                assertSingleCallWithCorrectParameters(command, initialDelay, period, unit);
                return new ThrowingScheduledFuture<>();
              }
            },
            testRunnable);
    assertTrue(called);
  }

    // this will happen once the interrupt has been set which means that
    // 1. the runner has been woken up
    // 2. the interrupter is stuck in the call the Thread.interrupt()

    // after some period of time the runner thread should become blocked on the task because it is
    // waiting for the slow interrupting thread to complete Thread.interrupt
    awaitBlockedOnInstanceOf(runner, InterruptibleTask.Blocker.class);

2.  APIs without `@Beta` will remain binary-compatible for the indefinite
    future. (Previously, we sometimes removed such APIs after a deprecation
    period. The last release to remove non-`@Beta` APIs was Guava 21.0.) Even
    `@Deprecated` APIs will remain (again, unless they are `@Beta`). We have no
    plans to start removing things again, but officially, we're leaving our

      return NeverScheduledFuture.create();
    }

    @Override
    public ListenableScheduledFuture<?> scheduleAtFixedRate(
        Runnable command, long initialDelay, long period, TimeUnit unit) {
      return NeverScheduledFuture.create();
    }

    @Override
    public ListenableScheduledFuture<?> scheduleWithFixedDelay(

 * specified the JVM flag {@code -XX:+DisableExplicitGC}. But in practice, it works very well for
 * ordinary tests.
 *
 * <p>Failure of the expected event to occur within an implementation-defined "reasonable" time
 * period or an interrupt while waiting for the expected event will result in a {@link
 * RuntimeException}.
 *
 * <p>Here's an example that tests a {@code finalize} method:
 *
 * <pre>{@code

      }
    }

    @Override
    public ListenableScheduledFuture<?> scheduleAtFixedRate(
        Runnable command, long initialDelay, long period, TimeUnit unit) {
      recordedCommand = command;
      recordedDelay = initialDelay;
      recordedInterval = period;
      recordedTimeUnit = unit;
      return ImmediateScheduledFuture.of("scheduleAtFixedRate");
    }

    @Override

    @Override
    public ListenableScheduledFuture<?> scheduleAtFixedRate(
        Runnable command, long initialDelay, long period, TimeUnit unit) {
      NeverSuccessfulListenableFutureTask task = new NeverSuccessfulListenableFutureTask(command);
      ScheduledFuture<?> scheduled = delegate.scheduleAtFixedRate(task, initialDelay, period, unit);
      return new ListenableScheduledTask<@Nullable Void>(task, scheduled);
    }

    @Override