public SecurityTokenProtector(ISecurityTokenKeyRing keyRing)
 {
     KeyRing = keyRing.NotNull(nameof(keyRing));
 }
 public PrivacyDataProtector(ISecurityTokenKeyRing keyRing, ISecurityTokenProtector protector)
 {
     _keyRing   = keyRing.NotNull(nameof(keyRing));
     _encryptor = protector.NotNull(nameof(keyRing));
 }