Cannot denormalize array

class Item
{
   public $id;

   //..getters and setters
}
$data = [['id' => 1], ['id' => 2]];

$serializer = new Serializer([new GetSetMethodNormalizer(), new ArrayDenormalizer()]);
$model = $serializer->denormalize($data, "Item[]");
dump($model);die;

And I'm getting error:

Could not denormalize object of type Item[], no supporting normalizer found.

All like in this example - https://symfony.com/doc/current/components/serializer.html#handling-arrays Why I'm getting error?