/// <summary>
 /// Create certificate request
 /// </summary>
 /// <param name="repo"></param>
 /// <param name="broker"></param>
 /// <param name="serializer"></param>
 public CertificateRequestManager(IRequestRepository repo,
                                  ICertificateRequestEventBroker broker, IJsonSerializer serializer)
 {
     _repo       = repo ?? throw new ArgumentNullException(nameof(repo));
     _serializer = serializer ?? throw new ArgumentNullException(nameof(serializer));
     _broker     = broker ?? throw new ArgumentNullException(nameof(broker));
 }
 /// <summary>
 /// Create processor
 /// </summary>
 /// <param name="repo"></param>
 /// <param name="entities"></param>
 /// <param name="broker"></param>
 /// <param name="logger"></param>
 public SigningRequestProcessor(IRequestRepository repo, IEntityInfoResolver entities,
                                ICertificateRequestEventBroker broker, ILogger logger)
 {
     _repo     = repo ?? throw new ArgumentNullException(nameof(repo));
     _logger   = logger ?? throw new ArgumentNullException(nameof(logger));
     _entities = entities ?? throw new ArgumentNullException(nameof(entities));
     _broker   = broker ?? throw new ArgumentNullException(nameof(broker));
 }
        /// <summary>
        /// Create certificate request
        /// </summary>
        /// <param name="keys"></param>
        /// <param name="serializer"></param>
        /// <param name="entities"></param>
        /// <param name="broker"></param>
        /// <param name="repo"></param>
        /// <param name="logger"></param>
        public KeyPairRequestProcessor(IRequestRepository repo, IKeyStore keys,
            IKeyHandleSerializer serializer, IEntityInfoResolver entities,
            ICertificateRequestEventBroker broker, ILogger logger) {

            _keys = keys ?? throw new ArgumentNullException(nameof(keys));
            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
            _repo = repo ?? throw new ArgumentNullException(nameof(repo));
            _broker = broker ?? throw new ArgumentNullException(nameof(broker));
            _entities = entities ?? throw new ArgumentNullException(nameof(entities));
            _serializer = serializer ?? throw new ArgumentNullException(nameof(serializer));
        }