code: public boolean isChild(final UIMenuItem _childItem,
                             final UIMenuItem _parentItem)
      {
          boolean ret = _parentItem.getChildren().contains(_childItem);
          if (!ret) {
              for (final UIMenuItem child : _parentItem.getChildren()) {
                  if (child.hasChildren()) {
                      ret = isChild(_childItem, child);
                  }
                  if (ret) {
                      break;
                  }
              }
          }
          return ret;
      }
docs: Is the Childitem a child/grandchild of the Parentitem.
  
  @param _childItem ChildItem
  @param _parentItem ParentItem
  @return true if child or grandchild etc.