@Test(expected = NullPointerException.class)
  public void testFilterShouldThrowNullPointerExceptionForNull() throws Exception {
    // Given:

    // When:
    underTest.filter(null);

    // Then: expect exception
  }
  @Test
  public void testFilterShould() throws Exception {
    // Given:
    Filter filter = Filter.ALL;

    // When:
    underTest.filter(filter);

    // Then:
    assertThat(underTest.getDescription().getChildren().size()).isGreaterThan(0);
  }