public void RegisterUser(string username) {
			AppUserService appUserService = new AppUserService();
			var appUser = appUserService.GetUserByUsername(username);

			if (appUser != null) {
				var connectionId = Context.ConnectionId;

				if (UsersNotifier.UsersConnections.ContainsKey(appUser.Id)) {
					UsersNotifier.UsersConnections[appUser.Id] = new UserFullDuplexConnection {ConnectionId = connectionId};
				} else {
					UsersNotifier.UsersConnections.Add(appUser.Id, new UserFullDuplexConnection {ConnectionId = connectionId});
				}
			}
		}
        public void RegisterUser(string username)
        {
            AppUserService appUserService = new AppUserService();
            var            appUser        = appUserService.GetUserByUsername(username);

            if (appUser != null)
            {
                var connectionId = Context.ConnectionId;

                if (UsersNotifier.UsersConnections.ContainsKey(appUser.Id))
                {
                    UsersNotifier.UsersConnections[appUser.Id] = new UserFullDuplexConnection {
                        ConnectionId = connectionId
                    };
                }
                else
                {
                    UsersNotifier.UsersConnections.Add(appUser.Id, new UserFullDuplexConnection {
                        ConnectionId = connectionId
                    });
                }
            }
        }