clientv3/balancer/picker/roundrobin_balanced.go
func NewRoundrobinBalanced(
	lg *zap.Logger,
	scs []balancer.SubConn,
	addrToSc map[resolver.Address]balancer.SubConn,
	scToAddr map[balancer.SubConn]resolver.Address,
) Picker {
	return &rrBalanced{
		lg:       lg,
		scs:      scs,
		addrToSc: addrToSc,
		scToAddr: scToAddr,
	}
}
func NewRoundrobinBalanced(
	lg *zap.Logger,
	scs []balancer.SubConn,
	addrToSc map[resolver.Address]balancer.SubConn,
	scToAddr map[balancer.SubConn]resolver.Address,
) Picker {
	return &rrBalanced{
		lg:       lg,
		scs:      scs,
		addrToSc: addrToSc,
		scToAddr: scToAddr,
	}
}
// NewRoundrobinBalanced returns a new roundrobin balanced picker.