public async Task <ActionResult <TbmSessionUser> > AddParticipant(TbmSessionUser tbmSessionUser)
        {
            if (_ijoinsService.TbmSessionUsersExists(tbmSessionUser.SessionId, tbmSessionUser.UserId))
            {
                return(Conflict());
            }

            return(await _ijoinsService.AddParticipant(tbmSessionUser));
        }