@abc.abstractmethod<EOL><INDENT>def get_items_by_learning_objective(self, objective_id):<DEDENT>
return<EOL>
Gets an ``ItemList`` containing the given learning objective.

        In plenary mode, the returned list contains all known items or
        an error results. Otherwise, the returned list may contain only
        those assessment items that are accessible through this session.

        :param objective_id: a learning objective ``Id``
        :type objective_id: ``osid.id.Id``
        :return: the returned ``Item`` list
        :rtype: ``osid.assessment.ItemList``
        :raise: ``NullArgument`` -- ``objective_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure occurred

        *compliance: mandatory -- This method must be implemented.*