Partial depth messages contain no symbol field?

Websocket
1

I have subscribed to a partial depth stream:

@depth@100ms

for 500+ symbols on the same websocket.

but the received message contains nothing to identify the symbol?

{“lastUpdateId”:657657678,“bids”:[],“asks”:[]}

How are we to identify which symbol the message belongs to?

2

if you wish to use the combine mode that server will return the stream name in the response message.

for example:

wss://stream.binance.com/stream?streams=bnbusdt@depth@100ms/ethusdt@depth@100ms