def METHOD_NAME(self, widget, context, x, y, data, info, stamp):
    uris = data.get_uris()
    tracks, playlists = self.tree.get_drag_data(uris)
    tracks = [
        t for t in tracks if not self.collection.loc_is_member(t.get_loc_for_io())
    ]
    self.add_tracks_func(tracks)