{in: IPNet{IP: badaddr, Mask: v4mask}},
	{in: IPNet{IP: badaddr, Mask: v4mappedv6mask}},
	{in: IPNet{IP: badaddr, Mask: v6mask}},
	{in: IPNet{IP: badaddr, Mask: badmask}},
}

func TestNetworkNumberAndMask(t *testing.T) {
	for _, tt := range networkNumberAndMaskTests {
		ip, m := networkNumberAndMask(&tt.in)
		out := &IPNet{IP: ip, Mask: m}
		if !reflect.DeepEqual(&tt.out, out) {