code: @Route(method = HttpMethod.GET, uri = "/assets")
      public Result index() {
          if (configuration.isProd()) {
              // Dumping assets is not enabled in PROD mode,
              // returning a bad request result
              return badRequest("Sorry, no asset dump in PROD mode.");
          }
  
          if (cache.isEmpty()  || NOCACHE_VALUE.equalsIgnoreCase(context().header(CACHE_CONTROL))) {
              // Refresh the cache.
              all();
          }
  
          return Negotiation.accept(ImmutableMap.of(
                  MimeTypes.HTML, ok(render(template, "assets", cache)),
                  MimeTypes.JSON, ok(cache).json()
          ));
      }
docs: Serves the asset list page, or a JSON form depending on the {@literal ACCEPT} header.
  @return the page, the json form or a bad request. Bad request are returned in "PROD" mode.