How to use the hap-nodejs.Characteristic.LockTargetState function in hap-nodejs

}, function(err, response, body) {

    if (!err && response.statusCode == 200) {
      this.log("State change complete.");
      
      // we succeeded, so update the "current" state as well
      var currentState = (state == Characteristic.LockTargetState.SECURED) ?
        Characteristic.LockCurrentState.SECURED : Characteristic.LockCurrentState.UNSECURED;
      
      this.service
        .setCharacteristic(Characteristic.LockCurrentState, currentState);
      
      callback(null); // success
    }
    else {
      this.log("Error '%s' setting lock state. Response: %s", err, body);
      callback(err || new Error("Error setting lock state."));
    }
  }.bind(this));
},

LockitronAccessory.prototype.setState = function(state, callback) {
  var lockitronState = (state == Characteristic.LockTargetState.SECURED) ? "lock" : "unlock";

  this.log("Set state to %s", lockitronState);

  request.put({
    url: "https://api.lockitron.com/v2/locks/"+this.lockID,
    qs: { access_token: this.accessToken, state: lockitronState }
  }, function(err, response, body) {

    if (!err && response.statusCode == 200) {
      this.log("State change complete.");
      
      // we succeeded, so update the "current" state as well
      var currentState = (state == Characteristic.LockTargetState.SECURED) ?
        Characteristic.LockCurrentState.SECURED : Characteristic.LockCurrentState.UNSECURED;
      
      this.service

informationService
      .setCharacteristic(Characteristic.Manufacturer, "SmartHome")
      .setCharacteristic(Characteristic.Model, this.device.deviceFriendlyName)
      .setCharacteristic(Characteristic.SerialNumber, this.device.address);	
	  
	var lockMechanismService = new Service.LockMechanism();
	
	this.lockService = lockMechanismService;
	this.informationService = informationService;	
    
    lockMechanismService
      .getCharacteristic(Characteristic.LockTargetState)
      .on('set', this.setTargetLockState.bind(this));
	  
	lockMechanismService
	  .getCharacteristic(Characteristic.LockTargetState)
	  .on('get', this.getTargetLockState.bind(this));
	  
	lockMechanismService
	  .getCharacteristic(Characteristic.LockCurrentState)
	  .on('get', this.getLockCurrentState.bind(this));
    
    return [informationService, lockMechanismService];	
}

ISYLockAccessory.prototype.getServices = function() {
	var informationService = new Service.AccessoryInformation();
	
	informationService
      .setCharacteristic(Characteristic.Manufacturer, "SmartHome")
      .setCharacteristic(Characteristic.Model, this.device.deviceFriendlyName)
      .setCharacteristic(Characteristic.SerialNumber, this.device.address);	
	  
	var lockMechanismService = new Service.LockMechanism();
	
	this.lockService = lockMechanismService;
	this.informationService = informationService;	
    
    lockMechanismService
      .getCharacteristic(Characteristic.LockTargetState)
      .on('set', this.setTargetLockState.bind(this));
	  
	lockMechanismService
	  .getCharacteristic(Characteristic.LockTargetState)
	  .on('get', this.getTargetLockState.bind(this));
	  
	lockMechanismService
	  .getCharacteristic(Characteristic.LockCurrentState)
	  .on('get', this.getLockCurrentState.bind(this));
    
    return [informationService, lockMechanismService];	
}

function LockitronAccessory(log, config) {
  this.log = log;
  this.name = config["name"];
  this.accessToken = config["api_token"];
  this.lockID = config["lock_id"];
  
  this.service = new Service.LockMechanism(this.name);
  
  this.service
    .getCharacteristic(Characteristic.LockCurrentState)
    .on('get', this.getState.bind(this));
  
  this.service
    .getCharacteristic(Characteristic.LockTargetState)
    .on('get', this.getState.bind(this))
    .on('set', this.setState.bind(this));
}

ISYLockAccessory.prototype.handleExternalChange = function() {
	this.lockService
		.setCharacteristic(Characteristic.LockTargetState, this.getDeviceCurrentStateAsHK());
	this.lockService
		.setCharacteristic(Characteristic.LockCurrentState, this.getDeviceCurrentStateAsHK());
}