code: def pop(self, index=None):
          
          if index is None:
              index = len(self.real_list) - 1
  
          effect = self[index]
          returned = self.real_list.pop(index)
  
          self._items.remove(effect)
          return returned
docs: See :meth:`~pluginsmanager.observer.observable_list.ObservableList.pop()` method