code: function isPercentDigitDigit (text, start) {
          return text.charAt(start) === '%' && charHelper.isHexDigit(text.charAt(start + 1)) && charHelper.isHexDigit(text.charAt(start + 2));
      }
docs: Returns, whether the given text at start is in the form 'percent hex-digit hex-digit', like '%3F'
  @param text
  @param start
  @return {boolean|*|*}