code: func (r *Router) adapt(mc MiddlewareChain, h Handler, path string) httprouter.Handle {
  	return httprouter.Handle(func(rw http.ResponseWriter, req *http.Request, p httprouter.Params) {
  		runChains(&Context{
  			Context:     r.rootCtx,
  			Writer:      rw,
  			Request:     req,
  			Params:      p,
  			HandlerPath: path,
  		}, r.middleware, mc, h)
  	})
  }
docs: // adapt adapts given middleware chain and handler into a httprouter-style handle.