PHP in_array关联数组

Question

我有以下$ items PHP数组......

Array (
    [44567] => Order_Item Object (
        [extra_data:protected] => Array (
        [product_id] => 0
        [variation_id] => 0
    )
    [data:protected] => Array (
        [order_id] => 4432
        [name] => Test Product
        [product_id] => 99
    )
    [cache_group:protected] => order-items
    [object_read:protected] => 1
    )
)

我正在尝试使用in_array来查明它是否包含product_id 99，我试过...

if (in_array('99', $item['product_id'], true)) {
    echo 'DETECTED';
}

是否有人有类似的工作示例我可以看一下？