code: function SerialDeviceGuider(deviceLoader) {
    var self = this;
  
    // call super class
    DeviceGuider.call(this, deviceLoader);
  
    this.currentState.getDeviceByPort = function(port) {
      return _.find(self.currentState.plugged, function(d) {
        return d.get('portName') && port && d.get('portName').toLowerCase() === port.toLowerCase();
      });
    };
  
    this.currentState.getConnectedDeviceByPort = function(port) {
      return _.find(self.currentState.connected, function(d) {
        return d.get('portName') && port && d.get('portName').toLowerCase() === port.toLowerCase();
      });
    };
  }
docs: A serialdeviceguider emits 'plug' for new attached serial devices,
  'unplug' for removed serial devices, emits 'connect' for connected serial devices
  and emits 'disconnect' for disconnected serial devices.
  @param {SerialDeviceLoader} deviceLoader The deviceloader object.