code: function (app) {
      this.options = this.options || {}
      this.options.babel = this.options.babel || {}
      this.options.babel.optional = this.options.babel.optional || []
  
      if (this.options.babel.optional.indexOf('es7.decorators') === -1) {
        this.options.babel.optional.push('es7.decorators')
      }
  
      /* eslint-disable no-unused-expressions */
      this._super.init && this._super.init.apply(this, arguments)
      /* eslint-enable no-unused-expressions */
    }
docs: /* eslint-disable complexity