No more boilerplate code for extension attributes object instantiation

extension_attributes_initialization.php

<?php
// Before Magento 2.3
$extensionAttributes = $product->getExtensionAttributes();
if (null === $extensionAttributes) {
    /** @var \Magento\Catalog\Api\Data\ProductExtensionInterface $extensionAttributes */
    $extensionAttributes = $this->extensionAttributesFactory->create(ProductInterface::class);
    $product->setExtensionAttributes($extensionAttributes);
}
$myExtensionAttribute = $extensionAttributes->getMyExtensionAttribute();

// After Magento 2.3
$myExtensionAttribute = $product->getExtensionAttributes()->getMyExtensionAttribute();