public async Task <IEnumerable <Commentary> > GetComments(int promotionId)
{
string orderBy = "id";
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 commentsEntities = await premierLeagueRepository.GetCommentsAsync(promotionId, orderByLower);
return(mapper.Map <IEnumerable <Commentary> >(commentsEntities));
}