code: def get_score_system_id(self):
          
          # Implemented from template for osid.resource.Resource.get_avatar_template
          if not bool(self._my_map['scoreSystemId']):
              raise errors.IllegalState('this AssessmentTaken has no score_system')
          mgr = self._get_provider_manager('ID')
          if not mgr.supports_id_lookup():
              raise errors.OperationFailed('Id does not support Id lookup')
          lookup_session = mgr.get_id_lookup_session(proxy=getattr(self, "_proxy", None))
          lookup_session.use_federated_no_catalog_view()
          osid_object = lookup_session.get_id(self.get_score_system_id())
          return osid_object
docs: Gets a score system ``Id`` for the assessment.
  
          return: (osid.id.Id) - the grade system
          raise:  IllegalState - ``is_score()`` is ``false``
          *compliance: mandatory -- This method must be implemented.*