public async Task <ActionResult <IReadOnlyList <TrainingDayDTO> > > getEveryTrainingDay()
{
var spec = new GetExerciseSpecification();
var trainingDays = await _trainingDayRepo.ListOnlyAsync(spec);
if (trainingDays == null)
{
return(NotFound());
}
var changedTrainingDay = _mapper.Map <IReadOnlyList <TrainingDay>, IReadOnlyList <TrainingDayDTO> >(trainingDays);
return(Ok(changedTrainingDay));
}