Marshal an interface

[abh]

I was looking at converting a small existing system to use jsonapi.

The structure for my response handlers is

type FooResponse interface {
   ID() int
   Foos() FooList
  ...
}

var resp FooResponse

// a bunch of conditional logic that gets FooResponse set

	if err := jsonapi.MarshalPayload(w, resp); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}

For the other ways I use FooResponse, this makes a lot of sense. Can I add a method to the FooResponse interface that jsonapi would call to build the response? Glancing through the code nothing stands out, it seems like it'll only work with a "plain" struct or slice directly?