docs: def _delete(self):
          """Deletes this AssessmentSection from database.
  
          Will be called by AssessmentTaken._delete() for clean-up purposes.
  
          """
          collection = JSONClientValidated('assessment',
                                           collection='AssessmentSection',
                                           runtime=self._runtime)
          collection.delete_one({'_id': ObjectId(self.get_id().get_identifier())})