java.io.IOException: Unable to tunnel through proxy. Proxy returns "HTTP/1.1 407 Proxy Authentication Required

[PhamHuyThien]

Hello everyone
I get error 407 when I request to google or other https sites that use basic proxy
for example here:

HttpRequest httpRequest = HttpRequest.post ("https://google.com");
httpRequest.useProxy ("proxyhost", 8888);
httpRequest.proxyBasic ("username", "password");
httpRequest.send (param);
System.out.println (httpRequest.body ());

So how to fix?
thanks!