source: class RendererUtilsTest {
  
      private RendererUtils utils;
      @Inject
      private FacesContext facesContext;
      @Inject
      private ExternalContext externalContext;
  
      @Test
      public void when_getNestingForm_is_provided_with_component_which_hasnt_form_ancestor_then_null_is_returned() {
  
target:         // given
          UIComponent viewRoot = mock(UIViewRoot.class);
          UIComponent component1 = mock(UIComponent.class);
          UIComponent component2 = mock(UIComponent.class);
          when(component1.getParent()).thenReturn(component2);
          when(component2.getParent()).thenReturn(viewRoot);
  
          // when
          UIComponent result = utils.getNestingForm(component1);
  
          // then
          assertNull(result);
      }
  
  }