public async Task <string> GetNewCodeAsync(Guid?ParentId = null, int BoxesNumber = 2, char FirstCode = '0')
{
var lastCode = await NativeGetAll().Where(e => e.ItemGroupId == ParentId).MaxAsync(e => e.Code);
var parentCode = await _itemGroupRepo.NativeGetAll().Where(e => e.Id == ParentId).Select(e => e.Code).SingleOrDefaultAsync();
return(GenerateNewCode(lastCode, parentCode, BoxesNumber, FirstCode));
}
