public WearableExtender addAction(Action action) {
            mActions.add(action);
            return this;
        }
Add a wearable action to this notification.

<p>When wearable actions are added using this method, the set of actions that
show on a wearable device splits from devices that only show actions added
using {@link NotificationCompat.Builder#addAction}. This allows for customization
of which actions display on different devices.

@param action the action to add to this notification
@return this object for method chaining
@see NotificationCompat.Action
android/android_framework/base/src/main/java/github/tornaco/android/thanos/core/compat/NotificationCompat.java