// connection, use ReserveNewRequest instead.
func (cc *http2ClientConn) CanTakeNewRequest() bool {
	cc.mu.Lock()
	defer cc.mu.Unlock()
	return cc.canTakeNewRequestLocked()
}

// ReserveNewRequest is like CanTakeNewRequest but also reserves a
// concurrent stream in cc. The reservation is decremented on the
// next call to RoundTrip.