newResp func() Resp

	recycleReq  func(Req)
	recycleResp func(Resp)
}

func recycleFunc[RT RoundTripper](newRT func() RT) (newFn func() RT, recycle func(r RT)) {
	rAny := any(newRT())
	var rZero RT
	if _, ok := rAny.(Recycler); ok {
		return newRT, func(r RT) {
			if r != rZero {
				if rc, ok := any(r).(Recycler); ok {
					rc.Recycle()
				}
			}
		}
	}
	pool := sync.Pool{