How to perform asynchronous futures Depth Cache?

[1163849662]

My code doesn't have any output, can you give a correct example thanks

from binance import ThreadedWebsocketManager

def main(): dcm = ThreadedWebsocketManager()

start is required to initialise its internal loop

dcm.start()

def handle_depth_cache(depth_cache):
    print(f"symbol {depth_cache.symbol}")
    print("top 5 bids")
    print(depth_cache.get_bids()[:5])
    print("top 5 asks")
    print(depth_cache.get_asks()[:5])
    print("last update time {}".format(depth_cache.update_time))

dcm_name = dcm.start_futures_depth_socket(handle_depth_cache, symbol='BNBBTC')

dcm.join()

if name == "main": main()

[Mrfranken]

what is depth cache, could u explain what it aimed for?