def add(self, album, objects, object_type=None, **kwds):
        """
        Endpoint: /album/<id>/<type>/add.json

        Add objects (eg. Photos) to an album.
        The objects are a list of either IDs or Trovebox objects.
        If Trovebox objects are used, the object type is inferred
        automatically.
        Returns the updated album object.
        """
        return self._add_remove("add", album, objects, object_type,
                                **kwds)