Why there's always a { unhandled_data: { R: true, I: '1' } } data after websocket connected?

[cbwang2016]

No description provided.

[TheRealest]

I believe this is the response to the call to SubscribeToExchangeDeltas (see here: https://github.com/dparlevliet/node.bittrex.api/blob/master/node.bittrex.api.js#L229) -- the R: true means the response from the server was true, so you were successfully subscribed, and the I: '1' is the index of the request when it was received, so you can know which request this is the response for in case they are handled out of order.

If you try passing multiple market names to the .subscribe call you will see that you receive one of these for each.