public Bundle getExtras() {
            if (mExtras == null) {
                mExtras = new Bundle();
            }
            return mExtras;
        }
Get the current metadata Bundle used by this notification Builder.

<p>The returned Bundle is shared with this Builder.

<p>The current contents of this Bundle are copied into the Notification each time
{@link #build()} is called.

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