code: public void setTree(CmsTree<CmsTreeItem> tree) {
  
          m_tree = tree;
          for (Widget widget : m_children) {
              if (widget instanceof CmsTreeItem) {
                  ((CmsTreeItem)widget).setTree(tree);
              }
          }
      }
docs: Sets the tree to which this tree item belongs.<p>
  
  This is automatically called when this tree item or one of its ancestors is inserted into a tree.<p>
  
  @param tree the tree into which the item has been inserted