for _, tt := range dualStackTCPListenerTests {
		if !testableListenArgs(tt.network1, JoinHostPort(tt.address1, "0"), "") {
			t.Logf("skipping %s test", tt.network1+" "+tt.address1)
			continue
		}

		if !supportsIPv4map() && differentWildcardAddr(tt.address1, tt.address2) {
			tt.xerr = nil
		}
		var firstErr, secondErr error
		for i := 0; i < 5; i++ {
			lns, err := newDualStackListener()
			if err != nil {

}

func TestProhibitionaryDialArg(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	switch runtime.GOOS {
	case "plan9":
		t.Skipf("not supported on %s", runtime.GOOS)
	}
	if !supportsIPv4map() {
		t.Skip("mapping ipv4 address inside ipv6 address not supported")
	}

	ln, err := Listen("tcp", "[::]:0")
	if err != nil {
		t.Fatal(err)
	}
	defer ln.Close()