old_contents: import extend from './extend'
  
  
  /**
   * plugin
   *
   * @param {Object} Vue
   * @param {Object} opts
   */
  
  export default function (Vue, opts = { lang: 'en', locales: {} }) {
    defineConfig(Vue.config, opts.lang)
    extend(Vue, opts.locales)
  }
  
  
  /**
   * defineConfig
   *
   * This function define `lang` property to `Vue.config`.
   *
   * @param {Object} config
   * @param {String} lang
   * @private
   */
  
  function defineConfig (config, lang) {
    Object.defineProperty(config, 'lang', {
      get: () => { return lang },
      set: (val) => { lang = val }
    })
  }
  
new_contents: import extend from './extend'
  
  
  /**
   * install
   *
   * @param {Object} Vue
   * @param {Object} opts
   */
  
  export default function install (Vue, opts = { lang: 'en', locales: {} }) {
    defineConfig(Vue.config, opts.lang)
    extend(Vue, opts.locales)
  }
  
  
  /**
   * defineConfig
   *
   * This function define `lang` property to `Vue.config`.
   *
   * @param {Object} config
   * @param {String} lang
   * @private
   */
  
  function defineConfig (config, lang) {
    Object.defineProperty(config, 'lang', {
      get: () => { return lang },
      set: (val) => { lang = val }
    })
  }
  
  
  /**
   * install automaticlly 
   */
  
  if (typeof window !== 'undefined' && window.Vue) {
    window.Vue.use(install)
  }
  
subject: support automatically install for standalone