chain.go
func FinalHandler(h http.Handler) func(http.Handler) http.Handler {
	return func(_ http.Handler) http.Handler {
		return h
	}
}
func FinalHandler(h http.Handler) func(http.Handler) http.Handler {
	return func(_ http.Handler) http.Handler {
		return h
	}
}
// FinalHandler is a helper function to wrap the last http.Handler element
// in the ChainHandlers function.