{"tcp4", "127.0.0.1"},
	{"tcp4", "::ffff:127.0.0.1"},

	{"tcp6", ""},
	{"tcp6", "::"},

	{"tcp6", "::1"},
}

// TestTCPListener tests both single and double listen to a test
// listener with same address family, same listening address and
// same port.
func TestTCPListener(t *testing.T) {
	switch runtime.GOOS {
	case "plan9":
		t.Skipf("not supported on %s", runtime.GOOS)
	}