code: def remove_on_change(self, attr, *callbacks):
          ''' Remove a callback from this object '''
          if len(callbacks) == 0:
              raise ValueError("remove_on_change takes an attribute name and one or more callbacks, got only one parameter")
          _callbacks = self._callbacks.setdefault(attr, [])
          for callback in callbacks:
              _callbacks.remove(callbackf remove_on_change(self, attr, *callbacks):
          ''' Remove a callback from this object '''
          if len(callbacks) == 0:
              raise ValueError("remove_on_change takes an attribute name and one or more callbacks, got only one parameter")
          _callbacks = self._callbacks.setdefault(attr, [])
          for callback in callbacks:
              _callbacks.remove(callback)
docs: Remove a callback from this object