private void initFragments(Bundle savedInstanceState) {
    if (savedInstanceState != null) {
        // get saved fragments from saved instance
        fragment1 = (FirstFragment) getSupportFragmentManager().getFragment(savedInstanceState, TAG_FRAGMENT_1);
        fragment2 = (SecondFragment) getSupportFragmentManager().getFragment(savedInstanceState, TAG_FRAGMENT_2);
    } else {
        // create new fragments instances
        fragment1 = FirstFragment.newInstance();
        fragment2 = SecondFragment.newInstance();
    }
}