p.mu.Lock()
	if err != nil {
		c.err = err
	} else {
		cc.getConnCalled = true // already called by the net/http package
		p.addConnLocked(key, cc)
	}
	delete(p.addConnCalls, key)
	p.mu.Unlock()
	close(c.done)
}

// p.mu must be held
func (p *http2clientConnPool) addConnLocked(key string, cc *http2ClientConn) {
	for _, v := range p.conns[key] {
		if v == cc {
			return
		}
	}
	if p.conns == nil {