public async Task <IEnumerable <Workshop> > GetWorkshopsAsync(int groupId)
{
if (groupId <= 0)
{
throw new ArgumentException($"Argument {nameof(groupId)} can't be less or equal zero!");
}
var workshopsDtos = await workshopRepository.GetWorkshopsAsync(groupId);
var workshops = new List <Workshop>();
foreach (var workshopDto in workshopsDtos)
{
workshops.Add(workshopDto.ToWorkshop());
}
return(workshops);
}