void RequestLastFreeTransactions(EndPoint address)
        {
            var date    = db.GetLastTransaction().Date0;
            var message = new RequestTransactionsMessage(date);

            if (address != null)
            {
                net.SendMessageToPeer(message, address);
            }
            else
            {
                net.SendMessageToAllPeers(message);
            }
        }
        private void RequestTransaction(string hash, EndPoint peerAddress = null)
        {
            var list = new List <string>();

            list.Add(hash);
            var message = new RequestTransactionsMessage(list);

            if (peerAddress == null)
            {
                net.SendMessageToAllPeers(message);
            }
            else
            {
                net.SendMessageToPeer(message, peerAddress);
            }
        }