code: func (c Chain) Handler(h http.Handler) http.Handler {
  	if h == nil {
  		h = http.DefaultServeMux
  	}
  
  	for i := len(c.mw) - 1; i >= 0; i-- {
  		h = c.mw[i](h)
  	}
  	return h
  }
docs: // Handler returns an http.Handler for this chain.