public UserList VerifyCredentials(string format, string apiToken, string apiTokenSecret)
{
SinaApiService myApi = new SinaApiService();
string myResult = myApi.VerifyCredentials(format, consumerKey, consumerKeySecret, apiToken, apiTokenSecret);
XDocument doc = XDocument.Parse(myResult);
//return UserList.Parse(doc);
return UserList.Parse(doc.Root);
}