@abc.abstractmethod<EOL><INDENT>def get_relationship_rules_proxy_manager(self):<DEDENT>
return<EOL>
Gets the relationship rules proxy manager.

        :return: a ``RelationshipRulesProxyManager``
        :rtype: ``osid.relationship.rules.RelationshipRulesProxyManager``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_relationship_rules()`` is ``false``

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