code: function (settings) {
          var self = this;
  
          self._super(settings);
  
          self.on('click mousedown', function (e) {
            e.preventDefault();
          });
  
          self.on('click', function (e) {
            e.preventDefault();
  
            if (!self.disabled()) {
              self.checked(!self.checked());
            }
          });
  
          self.checked(self.settings.checked);
        }
docs: Constructs a new Checkbox instance with the specified settings.
  
  @constructor
  @param {Object} settings Name/value object with settings.
  @setting {Boolean} checked True if the checkbox should be checked by default.