// with options
{
  "presets": [
    [ "@babel/preset-env", {
      "targets": [
        "last 2 versions",
        "ie >= 9",
        "safari >= 8",
        "firefox >= 40",
        "chrome >= 40",
        "electron >= 6"
        ],
      "modules": false,
      "debug": true,
      "useBuiltIns": "entry"
    }]
  ],
  "plugins": [
    "@babel/plugin-transform-classes"
  ]
}