/**
  * Returns an instance
  * @return PlentymarketsSoapClient
  */
 public static function getInstance()
 {
     if (!self::$Instance instanceof self) {
         // Config
         $PlentymarketsConfig = PlentymarketsConfig::getInstance();
         // WSDL
         $wsdl = $PlentymarketsConfig->getApiWsdl() . '/plenty/api/soap/version114/?xml';
         //
         self::$Instance = new self($wsdl, $PlentymarketsConfig->getApiUsername(), $PlentymarketsConfig->getApiPassword());
     }
     return self::$Instance;
 }