func testTimeoutHandler(t *testing.T, mode testMode) {
	sendHi := make(chan bool, 1)
	writeErrors := make(chan error, 1)
	sayHi := HandlerFunc(func(w ResponseWriter, r *Request) {
		<-sendHi
		_, werr := w.Write([]byte("hi"))
		writeErrors <- werr
	})
	ctx, cancel := context.WithCancel(context.Background())
	h := NewTestTimeoutHandler(sayHi, cancelableTimeoutContext{ctx})