@Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    TwitterAuthConfig authConfig =
        new TwitterAuthConfig(Constants.TWITTER_KEY, Constants.TWITTER_SECRET);
    Fabric.with(this, new TwitterCore(authConfig), new Digits());

    authCallback =
        new AuthCallback() {
          @Override
          public void success(DigitsSession session, String phoneNumber) {
            Toast.makeText(getBaseContext(), "Success", Toast.LENGTH_LONG).show();
            startProfileActivity(phoneNumber);
          }

          @Override
          public void failure(DigitsException exception) {
            Toast.makeText(getBaseContext(), "Failure", Toast.LENGTH_LONG).show();
          }
        };

    setContentView(com.crimepunch.app.R.layout.activity_registration);

    DigitsAuthButton digitsButton = (DigitsAuthButton) findViewById(R.id.auth_button);
    digitsButton.setCallback(authCallback);

    if (session.getUser(this) != null) {
      startHomeActivity();
    }
  }
  private void setUpDigitsButton() {
    phoneButton = (DigitsAuthButton) findViewById(R.id.phone_button);
    phoneButton.setAuthTheme(R.style.AppTheme);
    phoneButton.setCallback(
        new AuthCallback() {
          @Override
          public void success(DigitsSession digitsSession, String phoneNumber) {
            SessionRecorder.recordSessionActive("Login: digits account active", digitsSession);
            Answers.getInstance().logEvent("login:digits:success");
            startThemeChooser();
          }

          @Override
          public void failure(DigitsException e) {
            Answers.getInstance().logEvent("login:digits:failure");
            Toast.makeText(
                    getApplicationContext(),
                    getResources().getString(R.string.toast_twitter_digits_fail),
                    Toast.LENGTH_SHORT)
                .show();
            Crashlytics.logException(e);
          }
        });
  }