docs: def model(self, *args, **kwargs):
          # type: (*Any, **Any) -> Part
          """Retrieve single KE-chain part model.
  
          Uses the same interface as the :func:`part` method but returns only a single pykechain
          :class:`models.Part` instance of category `MODEL`.
  
          If additional `keyword=value` arguments are provided, these are added to the request parameters. Please
          refer to the documentation of the KE-chain API for additional query parameters.
  
          :return: a single :class:`models.Part`
          :raises NotFoundError: When no `Part` is found
          :raises MultipleFoundError: When more than a single `Part` is found
          """
          kwargs['category'] = Category.MODEL
          _parts = self.parts(*args, **kwargs)
  
          if len(_parts) == 0:
              raise NotFoundError("No model fits criteria")
          if len(_parts) != 1:
              raise MultipleFoundError("Multiple models fit criteria")
  
          return _parts[0]