public async Task <SymptomDTO> AddSymptomAsync(SymptomDTO s)
        {
            var symptom = _symptomFactory.Transform(s);
            await _symptomRepository.AddAsync(symptom);

            return(_symptomFactory.Transform(symptom));
        }
 public DiseaseDTO Transform(Disease d)
 {
     return(new DiseaseDTO
     {
         Id = d.Id,
         Name = d.Name,
         Symptoms = d.DiseaseSymptoms.Select(ds => _symptomFactory.Transform(ds.Symptom)).ToList()
     });
 }