@abc.abstractmethod<EOL><INDENT>def get_grade_system_ids_by_gradebook(self, gradebook_id):<DEDENT>
return<EOL>
Gets the list of ``GradeSystem``  ``Ids`` associated with a ``Gradebook``.

        :param gradebook_id: ``Id`` of the ``Gradebook``
        :type gradebook_id: ``osid.id.Id``
        :return: list of related grade system ``Ids``
        :rtype: ``osid.id.IdList``
        :raise: ``NotFound`` -- ``gradebook_id`` is not found
        :raise: ``NullArgument`` -- ``gradebook_id`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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