public async Task <IEnumerable <Promotion> > GetPromotionsAsync(bool showComments, string orderBy)
{
var orderByLower = orderBy.ToLower();
if (!allowedOrderByValues.Contains(orderByLower))
{
throw new BadRequestOperationException($"invalid Order By value : {orderBy} the only allowed values are {string.Join(", ", allowedOrderByValues)}");
}
var promotionsEntities = await premierLeagueRepository.GetPromotionsAsync(showComments, orderByLower);
return(mapper.Map <IEnumerable <Promotion> >(promotionsEntities));
}