docs: def get_overridden_calculated_entry(self):
          """Gets the calculated entry this entry overrides.
  
          return: (osid.grading.GradeEntry) - the calculated entry
          raise:  IllegalState - ``overrides_calculated_entry()`` is
                  ``false``
          raise:  OperationFailed - unable to complete request
          *compliance: mandatory -- This method must be implemented.*
  
          """
          # Implemented from template for osid.resource.Resource.get_avatar_template
          if not bool(self._my_map['overriddenCalculatedEntryId']):
              raise errors.IllegalState('this GradeEntry has no overridden_calculated_entry')
          mgr = self._get_provider_manager('GRADING')
          if not mgr.supports_grade_entry_lookup():
              raise errors.OperationFailed('Grading does not support GradeEntry lookup')
          lookup_session = mgr.get_grade_entry_lookup_session(proxy=getattr(self, "_proxy", None))
          lookup_session.use_federated_gradebook_view()
          osid_object = lookup_session.get_grade_entry(self.get_overridden_calculated_entry_id())
          return osid_object