{
    "presets": [
        "es2015",
        "stage-3", // async/await
        "stage-1" //class static
    ],
    "plugins": [
        // 解决编译打包后 $export is not a function  异常
        ['transform-runtime', {
          helpers: false,
          polyfill: false,
          regenerator: true, }]
    ]
}