`new_dev = {
  "IPADDR"                 => @ipaddr,
  "BROADCAST"         => "",
  "NETWORK"             => "",
  "REMOTE_IPADDR" => @remote_ip,
  ....
}
#and then set specific keys like
if @prefix && !@prefix.empty?
  new_dev[""PREFIXLEN"] = @prefix
else
  new_dev[""NETMASK"] = @netmask
end
...