@Test
public void testChildAddRemove() {

    addChild("child1");
    assertThat(engine.getReferenceView().getId()).isEqualTo("myRoot");
    assertThat(engine.getReferenceView().getChildren()).hasSize(1);
    removeChild("child1");
    assertThat(engine.getReferenceView().getId()).isEqualTo("myRoot");
    assertThat(engine.getReferenceView().getChildren()).isEmpty();
}