code: public void setSenderId(String senderId) {
  		try {
  			JSONObject sender;
  			if (!isNull((KEY_SENDER))) {
  				sender = getJSONObject(KEY_SENDER);
  			} else {
  				sender = new JSONObject();
  				put(KEY_SENDER, sender);
  			}
  			sender.put(KEY_SENDER_ID, senderId);
  		} catch (JSONException e) {
  			ApptentiveLog.e(e, "Exception setting ApptentiveMessage's %s field.", KEY_SENDER_ID);
  			logException(e);
  		}
  	}
docs: For debugging only.