def get_id_admin_session(self):
Gets the session associated with the id admin service.

        return: (osid.id.IdAdminSession) - an ``IdAdminSession``
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented - ``supports_id_admin()`` is ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_id_admin()`` is ``true``.*