code: public void registerCandlestickCallback(final BitfinexCandlestickSymbol symbol,
  			final BiConsumer<BitfinexCandlestickSymbol, BitfinexCandle> callback) throws BitfinexClientException {
  
  		candleCallbacks.registerCallback(symbol, callback);
  	}
docs: Register a new candlestick callback
  @param symbol
  @param callback
  @throws BitfinexClientException