如何让babel只需要转换导入而不需要添加额外的代码呢？

我使用babel将Node.js代码从es6转换为es5，事情是Node.js自然支持cmd风格的require和class，它不需要像下面这样大量的附加代码

Object.defineProperty(exports, "__esModule", { value: true }); var _createClass = function() { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function(Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();