Error when connecting via http through proxy

[maestroant]

`using Yove.Http.Proxy;
using HttpClient = Yove.Http.HttpClient;

HttpClient client = new HttpClient()
{
Proxy = new HttpProxy(":")
{
Username = "",
Password = ""
}
};

string s = await client.GetString("http://google.com");`

the error occurs when connecting via "HTTP" -
Yove.Http.Exceptions.HttpResponseException: "[Client] | Status Code - ProxyAuthenticationRequired"
Https is fine!