internal void NouveauExercice()
{
var exercices = _service.ExerciceGetAll().ToList();
var currentExercice = _service.Exercice;
var annee = Convert.ToInt32(currentExercice.Annee);
while (exercices.Any(x => x.Annee == annee.ToString()))
{
annee++;
}
_service.ExerciceCreate(annee.ToString());
}