public void move() {
    LOGGER.info("move");
  }
@Test
  void testMove() {
    final var ballItem = new BallItem();
    final var ballThread = mock(BallThread.class);
    ballItem.setTwin(ballThread);

    ballItem.move();
    assertTrue(appender.logContains("move"));

    verifyNoMoreInteractions(ballThread);
    assertEquals(1, appender.getLogSize());
  }