code: public StringBuilder appendTo(StringBuilder builder) {
      builder.append(SEPARATOR);
      builder.append(jtIdentifier);
      builder.append(SEPARATOR);
      builder.append(idFormat.format(id));
      return builder;
    }
docs: Add the stuff after the "job" prefix to the given builder. This is useful,
  because the sub-ids use this substring at the start of their string.
  @param builder the builder to append to
  @return the builder that was passed in