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)); }