code: public static BitfinexOrderBookSymbol orderBook(final String currency, final String profitCurrency, 
      		final BitfinexOrderBookSymbol.Precision precision,
      		final BitfinexOrderBookSymbol.Frequency frequency, final int pricePoints) {
      	
          final String currencyNonNull = Objects.requireNonNull(currency).toUpperCase();
          final String profitCurrencyNonNull = Objects.requireNonNull(profitCurrency).toUpperCase();
          
          return orderBook(BitfinexCurrencyPair.of(currencyNonNull, profitCurrencyNonNull), precision, frequency, pricePoints);
      }
docs: Returns symbol for candlestick channel
  
  @param currency       of order book
  @param profitCurrency of order book
  @param precision      of order book
  @param frequency      of order book
  @param pricePoints    in initial snapshot
  @return symbol