ipList = set.NewStringSet()
	for _, ip := range mustGetLocalIPs() {
		if ip.To4() == nil {
			ipList.Add(ip.String())
		}
	}
	return
}

// getHostIP returns IP address of given host.
func getHostIP(host string) (ipList set.StringSet, err error) {
	addrs, err := globalDNSCache.LookupHost(GlobalContext, host)
	if err != nil {
		return ipList, err
	}

	ipList = set.NewStringSet()

		host           string
		expectedIPList set.StringSet
		expectedErr    error
	}{
		{"localhost", set.CreateStringSet("127.0.0.1"), nil},
	}

	for _, testCase := range testCases {
		ipList, err := getHostIP(testCase.host)
		switch {
		case testCase.expectedErr == nil:
			if err != nil {
				t.Fatalf("error: expected = <nil>, got = %v", err)
			}
		case err == nil: