def work_loop(self):
    while True:
        tiles = self.tiles_queue.get()
        if (tiles is None):
            return
        with self.tile_mgr.session():
            self.tile_mgr.remove_tile_coords(tiles)
def work_loop(self):
    while True:
        tiles = self.tiles_queue.get()
        if (tiles is None):
            return
        with self.tile_mgr.session():
            self.tile_mgr.remove_tile_coords(tiles)