@Override
  public void startAsync() throws Exception {
    doAction(Executable::startAsync);
  }
@Test
  public void shouldStartAll() throws Exception {
    // When:
    multiExecutable.startAsync();

    // Then:
    final InOrder inOrder = Mockito.inOrder(executable1, executable2);
    inOrder.verify(executable1).startAsync();
    inOrder.verify(executable2).startAsync();
    inOrder.verifyNoMoreInteractions();
  }