code: private Tuple<Number, String> parse(final String value) {
      Matcher matcher = SIZE.matcher(value);
      if (matcher.find()) {
        String number = matcher.group(1);
        String unit = matcher.group(_3);
        boolean round = get("css.round");
        Number num = Double.parseDouble(number);
        return new Tuple(round ? Math.round(num.doubleValue()) : num, unit);
      }
      return null;
    }
docs: Parse a css size unit value, like 10px or 18.919px and optionally round the value to the
  closest integer.
  
  @param value Value to parse.
  @return A tuple with a number and unit(px, em, etc...)