public static String RefreshAccessToken(TembooSession session, String client_id, String client_secret, String refreshToken )
{
Console.WriteLine("Refresh YouTube access token");
RefreshToken refreshTokenChoreo = new RefreshToken(session);
// Set inputs
refreshTokenChoreo.setClientSecret(client_secret);
refreshTokenChoreo.setRefreshToken(refreshToken);
refreshTokenChoreo.setAccessTokenEndpoint("https://accounts.google.com/o/oauth2/token");
refreshTokenChoreo.setClientID(client_id);
// Execute Choreo
RefreshTokenResultSet refreshTokenResults = refreshTokenChoreo.execute();
// Print results
Console.WriteLine(refreshTokenResults.Response);
string s_refresh = refreshTokenResults.Response;
JObject json_refresh = JObject.Parse(s_refresh);
string accessToken = (string)json_refresh["access_token"];
string expires = (string)json_refresh["expires_in"];
Console.WriteLine("New AccessToken = " + accessToken + " which expires in " + expires + " minutes.");
return accessToken;
}