code: public static <I extends Request, O extends Response>
      CompositeServiceEntry<I, O> ofRegex(Pattern regex, Service<I, O> service) {
          return new CompositeServiceEntry<>(PathMapping.ofRegex(regex), service);
      }
docs: Creates a new {@link CompositeServiceEntry} whose {@link Service} is bound at the path that matches
  the specified regular expression.
  
  @see PathMapping#ofRegex(Pattern)