code: func getImportedPolicyHeader(c context.Context, name string) (*importedPolicyHeader, error) {
  	e := &importedPolicyHeader{Name: name}
  	switch err := datastore.Get(c, e); {
  	case err == datastore.ErrNoSuchEntity:
  		return nil, nil
  	case err != nil:
  		return nil, transient.Tag.Apply(err)
  	}
  	return e, nil
  }
docs: // getImportedPolicyHeader loads importedPolicyHeader entity from the datastore.
  //
  // Returns (nil, nil) if there's no such entity.