net/ip.go
func NewNetwork(ipNet net.IPNet) Network {
	return Network{
		IPNet:  ipNet,
		Number: NewNetworkNumber(ipNet.IP),
		Mask:   NetworkNumberMask(NewNetworkNumber(net.IP(ipNet.Mask))),
	}
}
func NewNetwork(ipNet net.IPNet) Network {
	return Network{
		IPNet:  ipNet,
		Number: NewNetworkNumber(ipNet.IP),
		Mask:   NetworkNumberMask(NewNetworkNumber(net.IP(ipNet.Mask))),
	}
}
// NewNetwork returns Network built using given net.IPNet.