docs: <T extends Component> List<T> getFormRowChildren(AbstractComponentContainer container, final Class<T> cls) {
  
          final List<T> result = Lists.newArrayList();
          CmsVaadinUtils.visitDescendants(container, new Predicate<Component>() {
  
              public boolean apply(Component comp) {
  
                  if (cls.isAssignableFrom(comp.getClass())) {
                      result.add(cls.cast(comp));
                  }
                  return true;
              }
          });
          return result;
      }