@abc.abstractmethod<EOL><INDENT>def can_update_grades(self, grade_system_id):<DEDENT>
return<EOL>
Tests if this user can update ``Grades``.

        A return of true does not guarantee successful authorization. A
        return of false indicates that it is known updating a ``Grade``
        will result in a ``PermissionDenied``. This is intended as a
        hint to an application that may not wish to offer update
        operations to unauthorized users.

        :param grade_system_id: the ``Id`` of a ``GradeSystem``
        :type grade_system_id: ``osid.id.Id``
        :return: ``false`` if ``Grade`` modification is not authorized, ``true`` otherwise
        :rtype: ``boolean``
        :raise: ``NullArgument`` -- ``grade_system_id`` is ``null``

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