public boolean onNavigationItemSelectedDefaultBehaviour(final @NonNull MenuItem item) {
        launchActivity(this, item.getItemId());

        // Clear activity stack if the user actively navigates via the bottom navigation
        clearBackStack();

        // avoid weird transitions
        ActivityMixin.overrideTransitionToFade(this);
        return true;
    }
@return the menu item id which should be selected
main/src/main/java/cgeo/geocaching/activity/AbstractNavigationBarActivity.java