function getVendorFiles(files, isMainVendorFile) {
  return {
    headerFiles: files,
    inputFiles: isMainVendorFile ? ['addon-tree-output/**/*.js'] : [],
    footerFiles: isMainVendorFile ? ['vendor/ember-cli/vendor-suffix.js'] : [],
  };
}
\/*.js'
    ],
    footerFiles: [
      'vendor/ember-cli/vendor-suffix.js'
    ],
    annotation: 'Vendor JS'
  }
  ```

  @private
  @method getVendorFiles
  @param {Object} files A list of files to include into `<file-name>.js`
  @param {Boolean} isMainVendorFile Boolean flag to indicate if we are dealing with `vendor.js` file
  @return {Object} An object with lists of files to be concatenated into `vendor.js` file.