{
      MockExecutor mock = new MockExecutor();
      TestExecutor testExecutor = new TestExecutor(mock);
      Future<?> f = testExecutor.submit(doNothing());
      mock.assertLastMethodCalled("submit");
      f.get();
    }
    {
      MockExecutor mock = new MockExecutor();
      TestExecutor testExecutor = new TestExecutor(mock);
      Future<String> f = testExecutor.submit(doNothing(), RESULT_VALUE);

    {
      MockExecutor mock = new MockExecutor();
      TestExecutor testExecutor = new TestExecutor(mock);
      Future<?> f = testExecutor.submit(doNothing());
      mock.assertLastMethodCalled("submit");
      f.get();
    }
    {
      MockExecutor mock = new MockExecutor();
      TestExecutor testExecutor = new TestExecutor(mock);
      Future<String> f = testExecutor.submit(doNothing(), RESULT_VALUE);

        public void run() {}
      };

  public void testSchedule() {
    MockExecutor mock = new MockExecutor();
    TestExecutor testExecutor = new TestExecutor(mock);

    @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
    Future<?> possiblyIgnoredError = testExecutor.schedule(DO_NOTHING, 10, MINUTES);
    mock.assertLastMethodCalled("scheduleRunnable", 10, MINUTES);