code: func GetIPNetCanonical(nw *net.IPNet) *net.IPNet {
  	if nw == nil {
  		return nil
  	}
  	c := GetIPNetCopy(nw)
  	c.IP = c.IP.Mask(nw.Mask)
  	return c
  }
docs: // GetIPNetCanonical returns the canonical form for the passed network