@SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
    Future<?> possiblyIgnoredError1 = testExecutor.scheduleAtFixedRate(() -> {}, 3, 7, SECONDS);
    mock.assertLastMethodCalled("scheduleAtFixedRate", 3, 7, SECONDS);
  }

  private static final class WrappedCallable<T> implements Callable<T> {
    private final Callable<T> delegate;

  public void testScheduleAtFixedRate() throws Exception {
    Runnable command = () -> {};

    ListenableScheduledFuture<?> future =
        executorService.scheduleAtFixedRate(command, Duration.ofDays(2), Duration.ofHours(4));

    assertThat(future.get()).isEqualTo("scheduleAtFixedRate");
    assertThat(recordedCommand).isSameInstanceAs(command);
    assertThat(recordedTimeUnit).isEqualTo(NANOSECONDS);

   * execute/submit/schedule}, as in {@link CallerRunsPolicy}. This applies both to individually
   * submitted tasks and to collections of tasks submitted via {@code invokeAll}, {@code invokeAny},
   * {@code schedule}, {@code scheduleAtFixedRate}, and {@code scheduleWithFixedDelay}. In the case
   * of tasks submitted by {@code invokeAll} or {@code invokeAny}, tasks will run serially on the

   * execute/submit/schedule}, as in {@link CallerRunsPolicy}. This applies both to individually
   * submitted tasks and to collections of tasks submitted via {@code invokeAll}, {@code invokeAny},
   * {@code schedule}, {@code scheduleAtFixedRate}, and {@code scheduleWithFixedDelay}. In the case
   * of tasks submitted by {@code invokeAll} or {@code invokeAny}, tasks will run serially on the

    @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
    Future<?> possiblyIgnoredError1 = testExecutor.scheduleAtFixedRate(() -> {}, 3, 7, SECONDS);
    mock.assertLastMethodCalled("scheduleAtFixedRate", 3, 7, SECONDS);
  }

  private static final class WrappedCallable<T> implements Callable<T> {
    private final Callable<T> delegate;

    return delegate.schedule(wrapTask(task), delay, unit);
  }

  @Override
  public final ScheduledFuture<?> scheduleAtFixedRate(
      Runnable command, long initialDelay, long period, TimeUnit unit) {
    return delegate.scheduleAtFixedRate(wrapTask(command), initialDelay, period, unit);
  }

  @Override
  public final ScheduledFuture<?> scheduleWithFixedDelay(

      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(

      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(

      Callable<V> callable, long delay, TimeUnit unit);

  /**
   * @since 15.0 (previously returned ScheduledFuture)
   */
  @Override
  ListenableScheduledFuture<?> scheduleAtFixedRate(
      Runnable command, long initialDelay, long period, TimeUnit unit);

  /**
   * @since 15.0 (previously returned ScheduledFuture)
   */
  @Override
  ListenableScheduledFuture<?> scheduleWithFixedDelay(

        }
      };
    }

    /**
     * Returns a {@link Scheduler} that schedules the task using the {@link
     * ScheduledExecutorService#scheduleAtFixedRate} method.
     *
     * @param initialDelay the time to delay first execution
     * @param period the period between successive executions of the task
     * @since 33.4.0 (but since 28.0 in the JRE flavor)
     */