docs: def get_item_notification_session(self, item_receiver):
          """Gets the notification session for notifications pertaining to item changes.
  
          arg:    item_receiver (osid.assessment.ItemReceiver): the item
                  receiver interface
          return: (osid.assessment.ItemNotificationSession) - an
                  ``ItemNotificationSession``
          raise:  NullArgument - ``item_receiver`` is ``null``
          raise:  OperationFailed - unable to complete request
          raise:  Unimplemented - ``supports_item_notification()`` is
                  ``false``
          *compliance: optional -- This method must be implemented if
          ``supports_item_notification()`` is ``true``.*
  
          """
          if not self.supports_item_notification():
              raise errors.Unimplemented()
          # pylint: disable=no-member
          return sessions.ItemNotificationSession(runtime=self._runtime, receiver=item_receiver)