public override async Task OnConnectedAsync()
        {
            var me = Context.User.Identity.Name;

            _logger.Trace($"User {me} connected. ");
            var groups = await _groups.GetUsersGroups(me, 0, await _groups.GetUsersGroupsLength(me));

            var user = await _users.Get(me);

            _logger.Trace($"User {user.Login} found. Connection id: {Context.ConnectionId}");
            user.ConnectionId = Context.ConnectionId;
            await _users.Update(user);

            foreach (var @group in groups)
            {
                await Groups.AddToGroupAsync(Context.ConnectionId, @group.GroupGuid);
            }
            await base.OnConnectedAsync();
        }