func (r *Router) Handler(method, path string, handler http.Handler) {
	r.Handle(method, path,
		func(w http.ResponseWriter, req *http.Request, _ Params) {
			handler.ServeHTTP(w, req)
		},
	)
}
Handler is an adapter which allows the usage of an http.Handler as a
request handle. With go 1.7+, the Params will be available in the
request context under ParamsKey.
package httprouter
import "net/http"