def get_grader(self):
raise errors.Unimplemented()<EOL>
Gets the ``Resource`` that created this entry.

        return: (osid.resource.Resource) - the ``Resource``
        raise:  IllegalState - ``is_graded() is false or is_derived() is
                true``
        raise:  OperationFailed - unable to complete request
        *compliance: mandatory -- This method must be implemented.*