private void FacebookAuthHandler(BaseEvent message)
        {
            LoginEvents.FacebookAuthEvent castEvent = message as LoginEvents.FacebookAuthEvent;

            PlayFabClientAPI.LoginWithFacebook(new LoginWithFacebookRequest {
                CreateAccount = true, AccessToken = castEvent.accessToken
            },
                                               OnPlayfabFacebookAuthComplete,
                                               OnPlayfabFacebookAuthFailed
                                               );
        }
        private void FacebookAuthHandler(BaseEvent message)
        {
            LoginEvents.FacebookAuthEvent castEvent = message as LoginEvents.FacebookAuthEvent;

            Firebase.Auth.Credential credential =
                Firebase.Auth.FacebookAuthProvider.GetCredential(castEvent.accessToken);

            auth.SignInWithCredentialAsync(credential).ContinueWith(task =>
            {
                if (task.IsCanceled)
                {
                    Log("SignInWithCredentialAsync was canceled.", "ERR");
                    return;
                }
                if (task.IsFaulted)
                {
                    Log("SignInWithCredentialAsync encountered an error: " + task.Exception, "ERR");
                    return;
                }

                user = auth.CurrentUser;
                MessagingSystem.Instance.DispatchEvent(new LoginEvents.FacebookCredentialsLoginEvent());
            });
        }