func (rtr *Rotor) Choose() XID {
	rtr.Lock()
	defer rtr.Unlock()
	n := len(rtr.open)
	if n <= 0 {
		return XID{}
	}
	return rtr.open[rand.Intn(n)]
}
// Choose returns a randomly chosen XID.
Choose returns a randomly chosen XID.
// Choose returns a randomly chosen XID .
func (rtr *Rotor) Choose() XID {
	rtr.Lock()
	defer rtr.Unlock()
	n := len(rtr.open)
	if n <= 0 {
		return XID{}
	}
	return rtr.open[rand.Intn(n)]
}
func ( rtr * Rotor ) Choose ( ) XID { rtr . Lock ( ) defer rtr . Unlock ( ) n := len ( rtr . open ) if n <= 0 { return XID { } } return rtr . open [ rand . Intn ( n ) ] }
Choose returns a randomly chosen XID.
Choose returns a randomly chosen XID .