code: def add_properties_callbacks(cls):
      
      for name in cls._mutators:                                                 #pylint: disable=protected-access
          if not hasattr(cls, name):
              continue
          setattr(cls, name, properties_mutator(cls, name))
      for name in cls._operators:                                                #pylint: disable=protected-access
          if not hasattr(cls, name):
              continue
          setattr(cls, name, properties_operator(cls, name))
      for name in cls._ioperators:                                               #pylint: disable=protected-access
          if not hasattr(cls, name):
              continue
          setattr(cls, name, properties_mutator(cls, name, True))
      return cls
docs: Class decorator to add change notifications to builtin containers