/// <summary>
        /// Send a message to a particular recipient.
        /// </summary>
        public void SendMessage(NotificationMessage message)
        {
            if (recipients.ContainsKey(message.RecipientName))
            {
                NotificationClient client = recipients[message.RecipientName];

                client.EnqueueMessage(message);
            }
        }
        /// <summary>
        /// Called by a individual recipient to wait and receive a message.
        /// </summary>
        /// <returns>The message content</returns>
        public string GetMessage(string userName)
        {
            string messageContent = string.Empty;

            if (recipients.ContainsKey(userName))
            {
                NotificationClient client = recipients[userName];

                messageContent = client.DequeueMessage().MessageContent;
            }

            return(messageContent);
        }
 /// <summary>
 /// Join a user to the recipient list.
 /// </summary>
 public void Join(string userName)
 {
     recipients[userName] = new NotificationClient();
 }