code: private synchronized void handleFinishSendingPayload(PayloadData payload, boolean cancelled, String errorMessage, int responseCode, JSONObject responseData) {
  		sendingFlag = false; // mark sender as 'not busy'
  
  		try {
  			if (listener != null) {
  				listener.onFinishSending(this, payload, cancelled, errorMessage, responseCode, responseData);
  			}
  		} catch (Exception e) {
  			ApptentiveLog.e(e, "Exception while notifying payload listener");
  			logException(e);
  		}
  	}
docs: Executed when we're done with the current payload
  @param payload      - current payload
  @param cancelled    - flag indicating if payload Http-request was cancelled
  @param errorMessage - if not <code>null</code> - payload request failed
  @param responseCode - http-request response code
  @param responseData - http-reqeust response json (or null if failed)