Start AP with hidden IP

Looking at a different module
http://www.espruino.com/modules/EspruinoWiFi.js
This looks like the relevant place to make the modification.

/* Create a WiFi access point allowing stations to connect.
     ssid - the AP's SSID
     options.password - the password - must be at least 8 characters (or 10 if all numbers)
     options.authMode - "open", "wpa2", "wpa", "wpa_wpa2"
     options.channel - the channel of the AP
*/
exports.startAP = function(ssid, options, callback) {  
  options = options||{};
  if (!options.password || options.password.length<8) throw new Error("Password must be at least 8 characters");
  var enc = options.password?"3":"0"; // wpa2 or open
  if (options.authMode) {
    enc={
      "open":0,
      "wpa":2,
      "wpa2":3,
      "wpa_wpa2":4
    }[options.authMode];
    if (enc===undefined) throw new Error("Unknown authMode "+options.authMode);
  }
  if (options.channel===undefined) options.channel=5;

  turnOn(MODE.AP, function(err) {
    if (err) return callback(err);
    at.cmd("AT+CWSAP="+JSON.stringify(ssid)+","+JSON.stringify(options.password)+","+options.channel+","+enc+"\r\n", 5000, function(cwm) {
      if (cwm!="OK") callback("CWSAP failed: "+(cwm?cwm:"Timeout"));
      else callback(null);        
    });
  });
};