PHP Soap og postdk

PHP kode 

 <?php
 /**
  * Created by JetBrains PhpStorm.
  * User: nick
  * Date: 21/05/12
  * Time: 13:46
  * To change this template use File | Settings | File Templates.
  */
 
 class PostDK
 {
 
     private static $instance = null;
 
     private $postDkUrl = 'http://www2.postdanmark.dk/webpack2demo/ParcelLabelWsService?wsdl';
     private $client;
 
     public function __construct() {
         $this->client = new SoapClient($this->postDkUrl,array("trace" => 1,"exceptions" => 1));
     }
 
     public static function getInstance() {
         if(!self::$instance) {
             self::$instance = new PostDK();
         }
         return self::$instance;
 
     }
 
     public function getParcelDepots($para){
 
         $parameter = array(
             "authentication" => array(
                 "customerNo" => $para['customerNo'],
                 "password" => $para['password']
             ));
         return $this->client->getParcelDepots($parameter);
 
     }
         /**
      * @return array
      * At kunden kan få generelle informationer om evt. ændringer eller nede tid, det være sig planlagt eller pga. evt. nedbrud.
      */
     public function showGeneralInfo(){
         return $this->client->showGeneralInfo();
     }
 
     /**
      * @return array
      * retunere et array med version info
      */
     public function getVersion(){
         return $this->client->getVersion();
     }
 
     public function lastRequest(){
         return $this->client->__getLastRequest();
     }
 
     public function lastResponse(){
         return $this->client->__getLastResponse();
     }
 
     /**
      * @return array
      * retunere et array af metoder der er tilgængelig hos postdk
      */
     public function getFunctions(){
         return $this->client->__getFunctions();
     }
 
     public function getTypes(){
         return $this->client->__getTypes();
     }
 }
     
  ?>