Returns a query set matching all connected objects with the given
        object as a destination.

def connected_to_objects(self, to_obj):
        """
        Returns a query set matching all connected objects with the given
        object as a destination.
        """
        return self.from_content_type.get_all_objects_for_this_type(pk__in=self.connected_to_object_ids(to_obj))