code: func cacheUnmanagedCertificatePEMBytes(certBytes, keyBytes []byte) error {
  	cert, err := makeCertificate(certBytes, keyBytes)
  	if err != nil {
  		return err
  	}
  	cacheCertificate(cert)
  	return nil
  }
docs: // cacheUnmanagedCertificatePEMBytes makes a certificate out of the PEM bytes
  // of the certificate and key, then caches it in memory.
  //
  // This function is safe for concurrent use.