code: def parts(self, *args, **kwargs):
          
          return self._client.parts(*args, activity=self.id, **kwargs)
docs: Retrieve parts belonging to this activity.
  
          Without any arguments it retrieves the Instances related to this task only.
  
          This call only returns the configured properties in an activity. So properties that are not configured
          are not in the returned parts.
  
          See :class:`pykechain.Client.parts` for additional available parameters.
  
          Example
          -------
          >>> task = project.activity('Specify Wheel Diameter')
          >>> parts = task.parts()
  
          To retrieve the models only.
          >>> parts = task.parts(category=Category.MODEL)