cc.nextStreamID += 2
	cc.streams[cs.ID] = cs
	if cs.ID == 0 {
		panic("assigned stream ID 0")
	}
}

func (cc *http2ClientConn) forgetStreamID(id uint32) {
	cc.mu.Lock()
	slen := len(cc.streams)
	delete(cc.streams, id)
	if len(cc.streams) != slen-1 {
		panic("forgetting unknown stream id")
	}
	cc.lastActive = time.Now()
	if len(cc.streams) == 0 && cc.idleTimer != nil {