code: private static String stripMarginFromLine(String line, char marginChar) {
          int length = line.length();
          int index = 0;
          while (index < length && line.charAt(index) <= ' ') index++;
          return (index < length && line.charAt(index) == marginChar) ? line.substring(index + 1) : line;
      }
docs: TODO expose this for other usage scenarios, e.g. stream based stripping?