public IHttpActionResult GetProducts(int pageSize = 10)
 {
     try
     {
         int pageNo   = 0;
         int IsPaging = 0;
         DataOperationService dataOperationService = new DataOperationService();
         List <Product>       products             = dataOperationService.GetProductsAsync(pageNo, pageSize, IsPaging).GetAwaiter().GetResult();
         return(Ok(products));
     }
     catch
     {
         throw;
     }
 }