PopBackStack on Nested Child Fragments

PopBackStack

@Override
    public void onBackPressed() {
        for (Fragment fragment : fragmentManager.getFragments()) {
            if (fragment.isVisible() && hasBackStack(fragment)) {
                if (popFragment(fragment))
                    return;
            }
        }
        super.onBackPressed();
    }

    private boolean hasBackStack(Fragment fragment) {
        FragmentManager childFragmentManager = fragment.getChildFragmentManager();
        return childFragmentManager.getBackStackEntryCount() > 0;
    }

    private boolean popFragment(Fragment fragment) {
        FragmentManager fragmentManager = fragment.getChildFragmentManager();
        for (Fragment childFragment : fragmentManager.getFragments()) {
            if (childFragment.isVisible()) {
                if (hasBackStack(childFragment)) {
                    return popFragment(childFragment);
                } else {
                    fragmentManager.popBackStack();
                    return true;
                }
            }
        }
        return false;
    }