code: func GetMinimalIPNet(nw *net.IPNet) *net.IPNet {
  	if nw == nil {
  		return nil
  	}
  	if len(nw.IP) == 16 && nw.IP.To4() != nil {
  		m := nw.Mask
  		if len(m) == 16 {
  			m = m[12:16]
  		}
  		return &net.IPNet{IP: nw.IP.To4(), Mask: m}
  	}
  	return nw
  }
docs: // GetMinimalIPNet returns a copy of the passed IP Network with congruent ip and mask notation