public static void Main (string[] args) {
String str = "Hello World! 你好，中国！";
String key = "1234567890";
String encrypt_data = XXTEA.EncryptToBase64String(str, key);
Console.WriteLine(encrypt_data);
Debug.Assert("QncB1C0rHQoZ1eRiPM4dsZtRi9pNrp7sqvX76cFXvrrIHXL6" == encrypt_data);
String decrypt_data = XXTEA.DecryptBase64StringToString(encrypt_data, key);
Debug.Assert(str == decrypt_data);
}