code: func (c *Context) Next(w http.ResponseWriter, r *http.Request) {
  	if c.route == nil {
  		return
  	}
  
  	if next := c.route.next; next != nil {
  		c.route = next
  		next.ServeHTTPContext(w, r, c)
  	} else {
  		c.holdUp = true
  	}
  }
docs: // Next invoke next route with the given ResponseWriter and Request