Simple helper function that makes it easier to understand:

<?php

function createLazyGhost(
    string $class,
    ?callable $initializer = null,
    ?array $propertySetterCallables = null
): object {
    $reflection = new ReflectionClass($class);

    return $reflection->newLazyGhost(function (object $object) use ($initializer, $propertySetterCallables) {
        // Initialize via the main initializer if provided
        if ($initializer) {
            $initializer($object);
        }

        // Set properties using the callables if provided
        if ($propertySetterCallables) {
            foreach ($propertySetterCallables as $property => $callable) {
                if (is_callable($callable)) {
                    $object->$property = $callable();
                }
            }
        }
    });
}

?>

This supports using either a main object initializer and/or property initializers.

Here's an example, where generating order IDs and calculating totals is considered expensive, so we only do it when necessary:

<?php

class Order {
    public string $orderId = '';
    public float $total = 0.0;
}

$initializer = function (Order $order) {
    $order->orderId = 'ORD12345';
};

$propertySetters = [
    'total' => fn() => 200.75,
];

// Lazy ghost with both an initializer and property callables
$lazyOrder = createLazyGhost(Order::class, $initializer, $propertySetters);

// We can now use $lazyOrder as normal, even though the properties haven't been calculated yet.

// Do something that triggers initialization
echo $lazyOrder->orderId . PHP_EOL;
echo $lazyOrder->total . PHP_EOL;

?>