public void setup() throws WorkflowException {
super.setup();
/* Set the output message to null to set teh output from async Listener */
WSIFAsyncResponsesCorrelator correlator;
if (this.messageBoxURL == null || this.messageBoxURL.length() == 0) {
correlator = new XsulSoapHttpWsaResponsesCorrelator();
String serverLoc = ((XsulSoapHttpWsaResponsesCorrelator) correlator).getServerLocation();
logger.debug("using async correlator at " + serverLoc);
} else {
correlator = new MsgBoxWsaResponsesCorrelator(this.messageBoxURL,this);
logger.debug("using message box at " + this.messageBoxURL);