code: func (s *Server) Before(handlers ...http.HandlerFunc) {
  	original := s.handlerFn
  	s.handlerFn = func(w http.ResponseWriter, r *http.Request) {
  		for _, handler := range handlers {
  			handler(w, r)
  		}
  		original(w, r)
  	}
  }
docs: // Before applys any http.HandlerFunc to the request before
  // sending it on to the controller/processor. Note that if a
  // handler incecepts the body of the request via request.Body
  // they must ensure it's contents are added back to request
  // or signature verification will fail!