@abc.abstractmethod<EOL><INDENT>def get_items_by_query(self, item_query):<DEDENT>
return<EOL>
Gets a list of ``Items`` matching the given item query.

        :param item_query: the item query
        :type item_query: ``osid.assessment.ItemQuery``
        :return: the returned ``ItemList``
        :rtype: ``osid.assessment.ItemList``
        :raise: ``NullArgument`` -- ``item_query`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure occurred
        :raise: ``Unsupported`` -- ``item_query`` is not of this service

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