@abc.abstractmethod<EOL><INDENT>def get_grade_systems_by_genus_type(self, grade_system_genus_type):<DEDENT>
return<EOL>
Gets a ``GradeSystemList`` corresponding to the given grade system genus ``Type`` which does not include systems of genus types derived from the specified ``Type``.

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

        :param grade_system_genus_type: a grade system genus type
        :type grade_system_genus_type: ``osid.type.Type``
        :return: the returned ``GradeSystem`` list
        :rtype: ``osid.grading.GradeSystemList``
        :raise: ``NullArgument`` -- ``grade_system_genus_type`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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