patree.go
func (r *Route) UseHandler(h Handler) {
	if r.f == nil {
		r.f = h
		return
	}

	route := r.getLeaf()
	route.next = &Route{f: h}
}
func (r *Route) UseHandler(h Handler) {
	if r.f == nil {
		r.f = h
		return
	}

	route := r.getLeaf()
	route.next = &Route{f: h}
}
func ( r * Route ) UseHandler ( h Handler ) { if r . f == nil { r . f = h return } route := r . getLeaf ( ) route . next = & Route { f : h } }
// UseHandler appends a Handler to the route.
UseHandler appends a Handler to the route .