public Builder addExtras(Bundle extras) {
            if (extras != null) {
                if (mExtras == null) {
                    mExtras = new Bundle(extras);
                } else {
                    mExtras.putAll(extras);
                }
            }
            return this;
        }
Merge additional metadata into this notification.

<p>Values within the Bundle will replace existing extras values in this Builder.

@see Notification#extras
android/android_framework/base/src/main/java/github/tornaco/android/thanos/core/compat/NotificationCompat.java