def get_objective_bank_notification_session(self, objective_bank_receiver=None):
raise Unimplemented()<EOL>
Gets the notification session for notifications pertaining to
        objective bank service changes.

        arg:    objectiveBankReceiver
                (osid.learning.ObjectiveBankReceiver): the objective
                bank receiver
        return: (osid.learning.ObjectiveBankNotificationSession) - an
                ObjectiveBankNotificationSession
        raise:  NullArgument - objectiveBankReceiver is null
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented - supports_objective_bank_notification()
                is false
        compliance: optional - This method must be implemented if
                    supports_objective_bank_notification() is true.