public List <ChallengeDTO> GetAllChallenges()
        {
            List <Challenge>    challenges    = challengeRepo.FindAll().OrderBy((a) => a.Name).ToList();
            List <ChallengeDTO> challengesDTO = new List <ChallengeDTO>();

            foreach (Challenge challenge in challenges)
            {
                challengesDTO.Add(new ChallengeDTO(challenge.MinimumAge, challenge.MaximumAge, challenge.Name,
                                                   entriesRepo.FindChildNumber(challenge.Id)));
            }

            return(challengesDTO);
        }