func mustGetHosts(t *testing.T, c cluster.Cluster) ([]iptables.IP, map[iptables.IP]int) {
var addrs []iptables.IP
addrsToNode := make(map[iptables.IP]int)
for i := 0; i < c.NumNodes(); i++ {
addr := iptables.IP(c.InternalIP(i).String())
addrsToNode[addr] = i
addrs = append(addrs, addr)
}
return addrs, addrsToNode
}