Continuation con = new Continuation(30);
    con.continuationMethod='processResponse';
    Http http = new Http();
    HttpRequest req1 = new HttpRequest();
    Blob headerValue = Blob.valueOf(username1 + ':' + password1);
    System.debug('UserName:::'+username1+ ':' + 'Password::::' + password1+ ':' + 'URL::::' +url1+ ':' + 'AccessToken:::' +accesstoken+ ':' + 'EventId:::' +eventid);
    String authorizationHeader = 'BASIC ' +  EncodingUtil.base64Encode(headerValue);
    req1.setHeader('Authorization', authorizationHeader);
    req1.setMethod('GET');
    req1.setEndpoint(url1+'/api/xml?action=report-event-participants-complete-information&account-id=1319228412&session='+accesstoken+'&sco-id='+eventid);
    res = http.send(req1);
    System.debug('Test Endpoint Request');
    this.requestLabel_1 = con.addHttpRequest(req1);
    return con;

}

public Object processResponse(){
    HttpResponse response1 = Continuation.getResponse(this.requestLabel_1);
    System.debug('Test1::'+response1);
    if(response1.getBody() != null && response1.getStatusCode() == 200)
    XMLparserUpdate s = new XMLparserUpdate(response1.getBody(),eventid,EventName);
    return null;