@abc.abstractmethod<EOL><INDENT>def get_grading_transform_manager(self):<DEDENT>
return<EOL>
Gets the ``GradingTransformManager``.

        :return: a ``GradingTransformManager``
        :rtype: ``osid.grading.transform.GradingTransformManager``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_grading_transform() is false``

        *compliance: optional -- This method must be implemented if
        ``supports_grading_transform()`` is true.*