function update($permissionItemId, KalturaPermissionItem $permissionItem)
 {
     $kparams = array();
     $this->client->addParam($kparams, "permissionItemId", $permissionItemId);
     $this->client->addParam($kparams, "permissionItem", $permissionItem->toParams());
     $this->client->queueServiceActionCall("permissionitem", "update", $kparams);
     if ($this->client->isMultiRequest()) {
         return null;
     }
     $resultObject = $this->client->doQueue();
     $this->client->throwExceptionIfError($resultObject);
     $this->client->validateObjectType($resultObject, "KalturaPermissionItem");
     return $resultObject;
 }