code: public static String normalize(String pidString)
              throws MalformedPIDException {
          if (pidString == null) {
              throw new MalformedPIDException("PID is null.");
          }
          
          return normalize(pidString, 0, pidString.length());
      }
docs: Return the normalized form of the given pid string, or throw a
  MalformedPIDException.
  @param pidString
  @return String normalized version of the pid
  @throws MalformedPIDException