Forbidding of creating objects outside factory in PHP with Reflection

php_factory_debug_reflection.php

<?php

class ClassA
{    
    public const FRIEND_CLASSES = [Factory::class];

    protected function __construct() {}
}

trait Constructor
{
    protected function createObject(string $className, array $args = [])
    {
        if (!in_array(static::class, $className::FRIEND_CLASSES)) {
            throw new \Exception("Call to private or protected {$className}::__construct() from invalid context");
        }
        $reflection = new ReflectionClass($className);
        $constructor = $reflection->getConstructor();
        $constructor->setAccessible(true);
        $object = $reflection->newInstanceWithoutConstructor();
        $constructor->invokeArgs($object, $args);
        return $object;
    }
}

class Factory
{
    use Constructor;

    public function createA(): ClassA
    {
        return $this->createObject(ClassA::class);
    }
}