code: @Route(method = HttpMethod.GET, uri = "/async/hello/{name}")
      public Result heavyComputation(@Parameter("name") final String name) {
          return async(new Callable<Result>() {
              @Override
              public Result call() throws Exception {
                  System.out.println(System.currentTimeMillis() + " - Heavy computation executed from " + Thread
                          .currentThread().getName());
                  Thread.sleep(10000);
                  System.out.println(System.currentTimeMillis() + " -  Heavy computation done " + Thread.currentThread
                          ().getName());
                  return ok("Hello " + name);
              }
          });
      }
docs: Waits ten second before sending the hello message.