code: func (x *XC) ExportPublicKey(ctx context.Context, id string) ([]byte, error) {
  	if x.pubring.Contains(id) {
  		return x.pubring.Export(id)
  	}
  	if x.secring.Contains(id) {
  		return x.secring.Export(id, false)
  	}
  	return nil, fmt.Errorf("key not found")
  }
docs: // ExportPublicKey exports a given public key