http/chain.go
func (s Chain) Get(handler http.Handler) http.Handler {
	for i := len(s) - 1; i >= 0; i-- {
		handler = s[i](handler)
	}
	return handler
}
func (s Chain) Get(handler http.Handler) http.Handler {
	for i := len(s) - 1; i >= 0; i-- {
		handler = s[i](handler)
	}
	return handler
}
// Get returns a HTTP handler which is a chain of middlewares and then the
// specified handler.