@abc.abstractmethod<EOL><INDENT>def get_resource_relationships_by_query(self, resource_relationship_query):<DEDENT>
return<EOL>
Gets a list of ``ResourceRelationship`` matching the given resource relationship query.

        :param resource_relationship_query: the resource relationship query
        :type resource_relationship_query: ``osid.resource.ResourceRelationshipQuery``
        :return: the returned ``ResourceRelationshipList``
        :rtype: ``osid.resource.ResourceRelationshipList``
        :raise: ``NullArgument`` -- ``resource_relationship_query is null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure
        :raise: ``Unsupported`` -- ``resource_relationship_query`` is not of this service

        *compliance: mandatory -- This method must be implemented.*