@Override
  public CeTaskResult getResult() {
    checkState(this.result != null, "No CeTaskResult has been set in the holder");
    return this.result;
  }
@Test
  public void getResult_throws_ISE_if_no_CeTaskResult_is_set() {
    assertThatThrownBy(() -> underTest.getResult())
      .isInstanceOf(IllegalStateException.class)
      .hasMessage("No CeTaskResult has been set in the holder");
  }