private bool AddParticipantToTable(int tableId) { List <GameTable> gameTableList = GameRepository.Instance.Get(); GameTable gameTable = gameTableList?.Find(table => table.Identifier.Equals(tableId)); if (ParticipationService.IsAlreadyParticipating(gameTable, User.Identity.Name)) { return(true); } return(ParticipationService.AddParticipation(gameTable, User.Identity.Name)); }