@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
  super.onRestoreInstanceState(bundle);
  EditText usernameEditText= (EditText)findViewById(R.id.username_edit_text);
  if (savedInstanceState.getString(Constants.USERNAME_EDIT_TEXT) != null) {
      usernameEditText.setText(savedInstanceState.getString(Constants.USERNAME_EDIT_TEXT));
  }
}