old_contents: def error_on_kwarg(func, kwargs):
      if kwargs:
          message = "{0}() got an unexpected keyword argument {1!r}"
          raise TypeError(message.format(func.__name__, next(iter(kwargs))))
  
  
  def convo_property(name):
      _name = '_' + name
      getter = lambda self: getattr(self, _name, getattr(self.cleverbot, name))
      setter = lambda self, value: setattr(self, _name, value)
      return property(getter, setter)
  
new_contents: def error_on_kwarg(func, kwargs):
      if kwargs:
          message = "{0}() got an unexpected keyword argument {1!r}"
          raise TypeError(message.format(func.__name__, next(iter(kwargs))))
  
  
  def convo_property(name):
      _name = '_' + name
      getter = lambda self: getattr(self, _name, getattr(self.cleverbot, name))
      setter = lambda self, value: setattr(self, _name, value)
      deleter = lambda self: delattr(self, _name)
      return property(getter, setter, deleter)
  
subject: Add deleter to Conversation properties