以下代碼來自dva庫。好多js庫里都有類似寫法，看不明白，不明覺厲。比如：_createDva2是干嘛用的？(0, _createDva2.default)(...) 這種寫法是什么鬼？__esModule似乎在很多庫里都有，它是啥嘞？Object.defineProperty(exports, "__esModule", {  value: true});var _reactRouter = require('react-router');var _reactRouterRedux = require('react-router-redux');var _createDva = require('./createDva');var _createDva2 = _interopRequireDefault(_createDva);function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }exports.default = (0, _createDva2.default)({  mobile: false,  initialReducer: {    routing: _reactRouterRedux.routerReducer  },  defaultHistory: _reactRouter.hashHistory,  routerMiddleware: _reactRouterRedux.routerMiddleware,  setupHistory: function setupHistory(history) {    this._history = (0, _reactRouterRedux.syncHistoryWithStore)(history, this._store);  }});module.exports = exports['default'];