code: def get_objective_objective_bank_session(self):
          
          if not self.supports_objective_objective_bank():
              raise errors.Unimplemented()
          # pylint: disable=no-member
          return sessions.ObjectiveObjectiveBankSession(runtime=self._runtime)
docs: Gets the session for retrieving objective to objective bank mappings.
  
          return: (osid.learning.ObjectiveObjectiveBankSession) - an
                  ``ObjectiveObjectiveBankSession``
          raise:  OperationFailed - unable to complete request
          raise:  Unimplemented - ``supports_objective_objective_bank()``
                  is ``false``
          *compliance: optional -- This method must be implemented if
          ``supports_objective_objective_bank()`` is ``true``.*