@abc.abstractmethod<EOL><INDENT>def set_grade(self, grade_id):<DEDENT>
pass<EOL>
Sets the grade.

        :param grade_id: the new grade
        :type grade_id: ``osid.id.Id``
        :raise: ``InvalidArgument`` -- ``grade_id`` is invalid or ``GradebookColumn.getGradeSystem().isBasedOnGrades()`` is ``false``
        :raise: ``NoAccess`` -- ``grade_id`` cannot be modified
        :raise: ``NullArgument`` -- ``grade_id`` is ``null``

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