@remove_null_proxy_kwarg<EOL><INDENT>def get_repository_hierarchy_design_session(self):<DEDENT>
<EOL>return self._provider_manager.get_repository_hierarchy_design_session()<EOL>
Gets the repository hierarchy design session.

        return: (osid.repository.RepositoryHierarchyDesignSession) - a
                ``RepostoryHierarchyDesignSession``
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented -
                ``supports_repository_hierarchy_design()`` is ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_repository_hierarchy_design()`` is ``true``.*