EntityToOrder::createBinding

protected function createBinding(ItemIdentifier $parent, ItemIdentifier $child): Result
{
	/** @var Order|null $order */
	$order = Order::load($child->getEntityId());
	if (!$order)
	{
		return (new Result())->addError(new Error('The child order does not exist: ' . $child));
	}

	$binding = $order->getEntityBinding() ?? $order->createEntityBinding();

	$binding->setField('OWNER_ID', $parent->getEntityId());
	$binding->setField('OWNER_TYPE_ID', $parent->getEntityTypeId());

	return $order->save();
}