#[Map(target: TargetEntity::class, transform: GetTargetEntityReference::class)]
class SourceDto {
	public string $id;
}

class GetTargetEntityReference implements TransformCallableInterface
{
    public function __construct(
        private readonly EntityManager $em,
        private readonly ObjectMapperMetadataFactoryInterface $metadata
    ){
    }

    public function __invoke(mixed $value, object $source, ?object $target): mixed
    {

        $metadata = $this->metadata->create($value);
        \assert(count($metadata) === 1);
        return $this->entityManager->getReference($metadata[0]->target, $value->id);
    }
}

}