private function setStockFor($item, $value)
 {
     $warehouse = $this->objFromFixture('ProductWarehouse', 'warehouse');
     $data = array('WarehouseID' => $warehouse->ID, 'ProductID' => $item->ID, 'ProductClass' => $item->getStockBaseIdentifier());
     $stock = ProductWarehouseStock::get()->filter($data)->first();
     if (!$stock) {
         $stock = new ProductWarehouseStock($data);
     }
     $stock->Quantity = $value;
     $stock->write();
 }
 /**
  * @return DataList
  */
 public function getWarehouseStock()
 {
     return ProductWarehouseStock::get()->filter(array('ProductID' => $this->owner->ID, 'ProductClass' => $this->getStockBaseIdentifier()));
 }