return err
}

// A timer is a time.Timer, as an interface which can be replaced in tests.
type http2timer = interface {
	C() <-chan time.Time
	Reset(d time.Duration) bool
	Stop() bool
}

// timeTimer adapts a time.Timer to the timer interface.
type http2timeTimer struct {
	*time.Timer
}

func (t http2timeTimer) C() <-chan time.Time { return t.Timer.C }

const (