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

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

   * 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

      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(

     */
    private void schedulePeriodicTasks() {
        // Heartbeat monitoring
        scheduler.scheduleAtFixedRate(this::checkHeartbeats, 30, 30, TimeUnit.SECONDS);

        // Registration monitoring
        scheduler.scheduleAtFixedRate(this::monitorRegistrations, 10, 10, TimeUnit.SECONDS);
    }

    /**
     * Registers for witness notifications.
     *

        this.scheduler = Executors.newScheduledThreadPool(1);
        this.changeNotifier = new DirectoryChangeNotifier(this);

        // Schedule periodic cache cleanup
        scheduler.scheduleAtFixedRate(this::cleanupExpiredEntries, 60, 60, TimeUnit.SECONDS);
    }

    /**
     * Request a directory lease
     *
     * @param directoryPath directory path
     * @param requestedState requested lease state

        }
      };
    }

    /**
     * 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 28.0 (but only since 33.4.0 in the Android flavor)

        }
      };
    }

    /**
     * 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)
     */

    RuntimeException ex = new RuntimeException();

    ListenableFuture<?> future;

    ThrowingRunnable runnable = new ThrowingRunnable(5, ex);
    future = service.scheduleAtFixedRate(runnable, 1, 1, MILLISECONDS);
    assertExecutionException(future, ex);
    assertEquals(5, runnable.count);
    assertEquals(0, delegate.getQueue().size());

    runnable = new ThrowingRunnable(5, ex);