code: func AuthoritiesToTrustedCerts(authorities []services.CertAuthority) []TrustedCerts {
  	out := make([]TrustedCerts, len(authorities))
  	for i, ca := range authorities {
  		out[i] = TrustedCerts{
  			ClusterName:      ca.GetClusterName(),
  			HostCertificates: ca.GetCheckingKeys(),
  			TLSCertificates:  services.TLSCerts(ca),
  		}
  	}
  	return out
  }
docs: // AuthoritiesToTrustedCerts serializes authorities to TrustedCerts data structure