public void Auth()
 {
     if (Social.localUser.authenticated)
     {
         GameCenterSignature.Generate(OnGeneratingSucceed, OnGeneratingFailed);
     }
     else
     {
         Social.localUser.Authenticate(OnLocalAuthenticateResult);
     }
 }
 private void OnLocalAuthenticateResult(bool success)
 {
     if (success)
     {
         Debug.Log("LocalAuthenticate success!");
         GameCenterSignature.Generate(OnGeneratingSucceed, OnGeneratingFailed);
     }
     else
     {
         Debug.Log("LocalAuthentificate failed.");
     }
 }