internal static string GetAuthorizationCode(
     TestUser acc,
     string scope,
     string redirectUri,
     string responseType)
 {
     return GetAuthorizationCode(
         (GoogleTestUser)acc,
         scope,
         redirectUri,
         responseType);
 }
 internal static string GetAccessToken(TestUser user)
 {
     return GetAccessToken((GoogleTestUser)user);
 }
 internal static void GetAccessToken(
     TestUser user, 
     out string access_token, 
     out string refresh_token, 
     out string token_type, 
     out int expires_in)
 {
     GetAccessToken(
         (GoogleTestUser) user, 
         out access_token, 
         out refresh_token, 
         out token_type, 
         out expires_in);
 }
 internal static void GetAccessToken(
     string authorizationCode,
     TestUser user,
     out string access_token,
     out string token_type,
     out int expires_in,
     out string refresh_token)
 {
     GetAccessToken(
         authorizationCode,
         (GoogleTestUser) user,
         out access_token,
         out token_type,
         out expires_in,
         out refresh_token);
 }
 internal static void GetAccessToken(
     TestUser user, 
     out string access_token, 
     out string refresh_token)
 {
     GetAccessToken(
         (GoogleTestUser) user,
         out access_token,
         out refresh_token);
 }