private Team TryAdd(Team aTeam)
        {
            TeamEntity entity = mapper.ToEntity(aTeam);
            Team       teamAdded;

            if (!Exists(entity.Sport.Name, entity.Name))
            {
                teamAdded = AddNew(aTeam);
            }
            else
            {
                throw new TeamAlreadyExistsException();
            }
            return(teamAdded);
        }