code: def _update_fields_with_objects(self):
          
          # Update the data with photo objects
          if self.type is not None:
              if self.type.startswith("photo"):
                  self.data = Photo(self._client, self.data)
              else:
                  raise NotImplementedError("Unrecognised activity type: %s"
                                            % self.type)
docs: Convert dict fields into objects, where appropriate