@abc.abstractmethod<EOL><INDENT>def get_relationship_query_session_for_family(self, family_id, proxy):<DEDENT>
return<EOL>
Gets the ``OsidSession`` associated with the relationship query service for the given family.

        :param family_id: the ``Id`` of the family
        :type family_id: ``osid.id.Id``
        :param proxy: a proxy
        :type proxy: ``osid.proxy.Proxy``
        :return: a ``RelationshipQuerySession``
        :rtype: ``osid.relationship.RelationshipQuerySession``
        :raise: ``NotFound`` -- no ``Family`` found by the given ``Id``
        :raise: ``NullArgument`` -- ``family_id`` or ``proxy`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_relationship_query()`` or ``supports_visible_federation()`` is ``false``

        *compliance: optional -- This method must be implemented if
        ``supports_relationship_query()`` and
        ``supports_visible_federation()`` are ``true``*