code: func ReadLocalIdentity(dataDir string, id IdentityID) (*Identity, error) {
  	storage, err := NewProcessStorage(context.TODO(), dataDir)
  	if err != nil {
  		return nil, trace.Wrap(err)
  	}
  	defer storage.Close()
  	return storage.ReadIdentity(IdentityCurrent, id.Role)
  }
docs: // ReadLocalIdentity reads, parses and returns the given pub/pri key + cert from the
  // key storage (dataDir).