如何在Stripe中将元数据添加到新订阅中？

I have this code, from the examples on Stripe API docs site:

stripe.Key = "my_key"

s, err := sub.New(&stripe.SubParams{
    Customer: "test_customer",
    Plan: "month-plan",

})

This code works just fine. But I couldn't find how to add metadata to this request, like Product: "special-services".

Can I do it in one request on subscription creation, and if so, then how?

Thanks!

subParams := &stripe.SubParams{
    Customer: "test_customer",
    Plan: "month-plan",
}
subParams.AddMeta("Product","special-services")
s, err := sub.New(subParams)

stripe.SubParams embeds stripe.Params which has a method AddMeta, which adds meta info to a map[string]string.