public function testProductDeliveriesSynchronization()
 {
     $provider = $this->getBaseProvider();
     $product = new Product();
     $delivery1 = new Delivery();
     $product->addDelivery($delivery1);
     $variation = $provider->createVariation($product, false);
     $this->assertEquals(0, count($variation->getDeliveries()));
     $provider->synchronizeVariationsDeliveries($product);
     $this->assertEquals(1, count($variation->getDeliveries()));
     $delivery2 = new Delivery();
     $product->addDelivery($delivery2);
     $this->assertEquals(1, count($variation->getDeliveries()));
     $provider->synchronizeVariationsDeliveries($product);
     $this->assertEquals(2, count($variation->getDeliveries()));
     $product->removeDelivery($delivery1);
     $this->assertEquals(2, count($variation->getDeliveries()));
     $provider->synchronizeVariationsDeliveries($product);
     $this->assertEquals(1, count($variation->getDeliveries()));
 }