public class Main {
    public static void main(String[] args) {
        //...

        // create an instance of HttpClient
        HttpClient client = HttpClient.newHttpClient();

        // build an HTTP request with a randomly selected User-Agent header
        HttpRequest request = HttpRequest.newBuilder()
            .uri(URI.create("https://httpbin.io/user-agent"))
            .header("User-Agent", randomUserAgent) // set a random User-Agent header
            .build();

        // send request asynchronously and print response to the console
        client.sendAsync(request, BodyHandlers.ofString())
            .thenApply(HttpResponse::body)
            .thenAccept(System.out::println)
            .join();
    }
}