@abc.abstractmethod<EOL><INDENT>def register_for_deleted_relationships_by_genus_type(self, relationship_genus_type):<DEDENT>
pass<EOL>
Register for notifications of deleted relationships.

        ``RelationshipReceiver.deletedRelationships()`` is invoked when
        a ``Relationship`` if removed for the given peer.

        :param relationship_genus_type: the genus type of the ``Relationship`` to monitor
        :type relationship_genus_type: ``osid.type.Type``
        :raise: ``NullArgument`` -- ``relationship_genus_type`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``PermissionDenied`` -- authorization failure

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