code: private void handleCommandCallback(final String message) {
  		// JSON callback
          final JSONObject jsonObject = new JSONObject(message);
  		final String eventType = jsonObject.getString("event");
  
  		final CommandCallbackHandler commandCallbackHandler = commandCallbacks.get(eventType);
  		if( commandCallbackHandler == null ) {
  			logger.error("Unknown event: {}", message);
  			return;
  		}
  		try {
  			commandCallbackHandler.handleChannelData(jsonObject);
  		} catch (final BitfinexClientException e) {
  			logger.error("Got an exception while handling callback");
  		}
  	}
docs: Handle a command callback