code: public static String urlFrom(Request request,
                                   String... pathSegments) {
          return urlFrom(request.uri(), pathSegments);
      }
docs: Creates an absolute url using the given request's url as base and appending optional segments.
  
  @param request      a {@code non-null} {@link RequestContext}
  @param pathSegments an option array of segments
  @return a string representing an absolute-url