public void start() {
    executor.execute(new Runner());
    executor.shutdown();
  }
@Test
  public void shouldSubmitTaskOnStart() {
    // When:
    commandRunner.start();

    // Then:
    final InOrder inOrder = inOrder(executor);
    inOrder.verify(executor).execute(any(Runnable.class));
    inOrder.verify(executor).shutdown();
  }