func (cc *http2ClientConn) decrStreamReservationsLocked() {
	if cc.streamsReserved > 0 {
		cc.streamsReserved--
	}
}

func (cc *http2ClientConn) RoundTrip(req *Request) (*Response, error) {
	return cc.roundTrip(req, nil)
}

func (cc *http2ClientConn) roundTrip(req *Request, streamf func(*http2clientStream)) (*Response, error) {
	ctx := req.Context()
	cs := &http2clientStream{
		cc:                   cc,