net/ip.go
func (n Network) Masked(ones int) Network {
	mask := net.CIDRMask(ones, len(n.Number)*BitsPerUint32)
	return NewNetwork(net.IPNet{
		IP:   n.IP.Mask(mask),
		Mask: mask,
	})
}
func (n Network) Masked(ones int) Network {
	mask := net.CIDRMask(ones, len(n.Number)*BitsPerUint32)
	return NewNetwork(net.IPNet{
		IP:   n.IP.Mask(mask),
		Mask: mask,
	})
}
// Masked returns a new network conforming to new mask.