@Nullable
    public static Bundle getExtras(Notification notification) {
        if (Build.VERSION.SDK_INT >= 19) {
            return notification.extras;
        } else if (Build.VERSION.SDK_INT >= 16) {
            return NotificationCompatJellybean.getExtras(notification);
        } else {
            return null;
        }
    }
Gets the {@link Notification#extras} field from a notification in a backwards
compatible manner. Extras field was supported from JellyBean (Api level 16)
forwards. This function will return {@code null} on older api levels.
android/android_framework/base/src/main/java/github/tornaco/android/thanos/core/compat/NotificationCompat.java