code: func statusCode(e kerrors.Error) int {
  	if e.Code > 0 {
  		return e.Code
  	}
  	switch e.Reference {
  	case kerrors.InternalError:
  		return http.StatusInternalServerError
  	case kerrors.InvalidData:
  		return http.StatusUnprocessableEntity
  	case kerrors.MalformedData:
  		return http.StatusBadRequest
  	case kerrors.Forbidden:
  		return http.StatusForbidden
  	case kerrors.NotFound:
  		return http.StatusNotFound
  	default:
  		return http.StatusInternalServerError
  	}
  }
docs: // statusCode returns the http status code for an error.