// IPv6 addresses of localhost.
	localIP6 = mustGetLocalIP6()

	// List of all local loopback addresses.
	localLoopbacks = mustGetLocalLoopbacks()
)

// mustSplitHostPort is a wrapper to net.SplitHostPort() where error is assumed to be a fatal.
func mustSplitHostPort(hostPort string) (host, port string) {
	xh, err := xnet.ParseHost(hostPort)
	if err != nil {
		logger.FatalIf(err, "Unable to split host port %s", hostPort)
	}

		{"server:54321", "server", "54321"},
		{":0", "", "0"},
		{"server:https", "server", "443"},
		{"server:http", "server", "80"},
	}

	for _, testCase := range testCases {
		host, port := mustSplitHostPort(testCase.hostPort)
		if testCase.expectedHost != host {
			t.Fatalf("host: expected = %v, got = %v", testCase.expectedHost, host)
		}

		if testCase.expectedPort != port {