for _, cc := range ccs {
			if cc.idleState().canTakeNewRequest {
				ret = append(ret, k)
			}
		}
	}

	slices.Sort(ret)
	return ret
}

func (t *Transport) IdleConnCountForTesting(scheme, addr string) int {
	t.idleMu.Lock()
	defer t.idleMu.Unlock()
	key := connectMethodKey{"", scheme, addr, false}
	cacheKey := key.String()
	for k, conns := range t.idleConn {

	if keys[0] != cacheKey {
		t.Fatalf("Expected idle cache key %q; got %q", cacheKey, keys[0])
	}
	if e, g := 1, tr.IdleConnCountForTesting("http", addr); e != g {
		t.Errorf("after first response, expected %d idle conns; got %d", e, g)
	}

	resch <- "res2"
	<-donech
	if g, w := tr.IdleConnCountForTesting("http", addr), 2; g != w {
		t.Errorf("after second response, idle conns = %d; want %d", g, w)
	}

	resch <- "res3"