/**
  * {@inheritdoc}
  */
 public function removeCategoryFromProduct(ProductInterface $product, CategoryInterface $category)
 {
     if (!($productCategory = $this->findOneBy(array('category' => $category, 'product' => $product)))) {
         return;
     }
     $product->removeProductCategory($productCategory);
     $this->delete($productCategory);
 }