babel/packages/babel-plugin-transform-es2015-parameters/test/fixtures/parameters/default-iife-4253/expected.js

var Ref = function Ref() {
  var id = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : ++Ref.nextID;
  babelHelpers.classCallCheck(this, Ref);
  this.id = id;
};

Ref.nextID = 0;