code: function onError (error) {
    switch (error.code) {
      case 'EACCES':
        throw new InternalServerError(error, 'Port require elevated privileges')
      case 'EADDRINUSE':
        throw new InternalServerError(error, 'Port is already in use')
      default:
        throw new InternalServerError(error, error.message)
    }
  }
docs: ────────────────────────────────  Private  ──────────────────────────────────