code: def emit_data_changed(self):
          
          item = self.get_treeitem()
          m = item.get_model()
          if m:
              start = m.index_of_item(item)
              parent = start.parent()
              end = m.index(start.row(), item.column_count()-1, parent)
              m.dataChanged.emit(start, end)
docs: Emit the data changed signal on the model of the treeitem
          if the treeitem has a model.
  
          :returns: None
          :rtype: None
          :raises: None