code: @SuppressWarnings("unchecked")
  	public JSONObject toJSONObject() {
  		final JSONObject activity = new JSONObject();
  
  		// parse time stamp
  		activity.put("published",
  				dateFormatter.format(new Date(this.timestamp)));
  
  		// TODO: check performance
  		// parse user
  		// final Map<String, Object> user = this.creator.toActorJSON();
  		// activity.put("actor", user);
  
  		// parse verb:read
  		activity.put("verb", "read");
  
  		// parse object
  		final Map<String, Object> object = this.toObjectJSON();
  		activity.put("object", object);
  
  		return activity;
  	}
docs: parse the status update to an Activity JSON String
  
  @return Activity JSON String representing this status update<br>
  (Activitystrea.ms)