code: func getRandomIPinSubnet(d *Driver, baseIP net.IP) (net.IP, error) {
  	var dhcpAddr net.IP
  
  	nAddr := baseIP.To4()
  	// select pseudo-random DHCP addr; make sure not to clash with the host
  	// only try 5 times and bail if no random received
  	for i := 0; i < 5; i++ {
  		n := d.randomInter.RandomInt(24) + 1
  		if byte(n) != nAddr[3] {
  			dhcpAddr = net.IPv4(nAddr[0], nAddr[1], nAddr[2], byte(n))
  			break
  		}
  	}
  
  	if dhcpAddr == nil {
  		return nil, ErrUnableToGenerateRandomIP
  	}
  
  	return dhcpAddr, nil
  }
docs: // getRandomIPinSubnet returns a pseudo-random net.IP in the same
  // subnet as the IP passed