private AppCompatDelegate getDelegate() {
        if (mDelegate == null) {
            mDelegate = AppCompatDelegate.create(this, null);
        }
        return mDelegate;
    }
A {@link android.preference.PreferenceActivity} which implements and proxies the necessary calls
to be used with AppCompat.
app/src/main/java/home/smart/fly/animations/AppCompatPreferenceActivity.java