get
Retrieves the unique ID that identifies this push notification. When using the broadcast push service from the developer console, this ID is used to track the push open rate. If you customize the display of push notifications, you must call recordNotificationEvent to upload the push open event when the notification is clicked. This ensures that RCbackend can accurately calculate the push open rate for you.
Return
When using the broadcast push service from the developer console, returns a string representing the pushId. If the push is converted from a message, it represents the message's UID.