code: func (c *Client) GetCertAuthority(id services.CertAuthID, loadSigningKeys bool, opts ...services.MarshalOption) (services.CertAuthority, error) {
  	if err := id.Check(); err != nil {
  		return nil, trace.Wrap(err)
  	}
  	out, err := c.Get(c.Endpoint("authorities", string(id.Type), id.DomainName), url.Values{
  		"load_keys": []string{fmt.Sprintf("%t", loadSigningKeys)},
  	})
  	if err != nil {
  		return nil, trace.Wrap(err)
  	}
  	return services.GetCertAuthorityMarshaler().UnmarshalCertAuthority(
  		out.Bytes(), services.SkipValidation())
  }
docs: // GetCertAuthority returns certificate authority by given id. Parameter loadSigningKeys
  // controls if signing keys are loaded