old_contents: import babel from 'rollup-plugin-babel';
  import babelrc from 'babelrc-rollup';
  
  const babelConfig = {
      "presets": [
          ["env", {
              "targets": {
                  "browsers": ["last 2 versions"]
              },
              "modules": false,
              "loose": true
          }]
      ]
  };
  
  export default {
    entry: 'src/alpha.js',
    format: 'umd',
    moduleName: 'Alpha',
    plugins: [
      babel(babelrc({
        addExternalHelpersPlugin: false,
        config: babelConfig,
        exclude: 'node_modules/**'
      }))
    ],
    dest: 'dist/bundle.js'
  };
new_contents: import babel from 'rollup-plugin-babel';
  import babelrc from 'babelrc-rollup';
  
  const babelConfig = {
    'presets': [
      ['env', {
        'targets': {
          'browsers': ['last 2 versions']
        },
        'modules': false,
        'loose': true
      }]
    ]
  };
  
  export default {
    entry: 'src/alpha.js',
    format: 'umd',
    moduleName: 'Alpha',
    plugins: [
      babel(babelrc({
        addExternalHelpersPlugin: false,
        config: babelConfig,
        exclude: 'node_modules/**'
      }))
    ],
    dest: 'dist/bundle.js'
  };
  
subject: Format rollup config