code: public static NewsstandNotificationPayload contentAvailable() {
  		NewsstandNotificationPayload payload = complex();
  		try {
  			payload.addContentAvailable();
  		} catch (JSONException e) {
  		}
  		return payload;
  	}
docs: Create a pre-defined payload with a content-available property set to 1.
  
  @return a ready-to-send newsstand payload