code: public static QuandlCodeRequest singleColumn(final String quandlCode, final int columnNumber) {
      ArgumentChecker.notNull(quandlCode, "quandlCode");
      return new QuandlCodeRequest(quandlCode, columnNumber);
    }
docs: Request just a single column for a given quandlCode.
  
  @param quandlCode the Quandl code you're interested in, not null
  @param columnNumber the column number (determined by meta-data or a single request) of the data you want, not null
  @return an request instance, not null