docs: def addMenuItem( self, newItem, atItem ):
          """
          Adds a new menu item at the given item.
          
          :param      newItem | <QTreeWidgetItem>
                      atItem  | <QTreeWidgetItem>
          """
          tree = self.uiMenuTREE
          
          if ( not atItem ):
              tree.addTopLevelItem(newItem)
              
          elif ( atItem.data(0, Qt.UserRole) == 'menu' ):
              atItem.addChild(newItem)
          
          elif ( atItem.parent() ):
              index = atItem.parent().indexOfChild(atItem)
              atItem.parent().insertChild(index + 1, newItem)
          
          else:
              index = tree.indexOfTopLevelItem(atItem)
              tree.insertTopLevelItem(index + 1, newItem)