public CarvedRockMutation(IProductReviewRepository productReviewRepository)
 {
     FieldAsync <ProductReviewType>(
         "createReview",
         arguments: new QueryArguments(
             new QueryArgument <NonNullGraphType <ProductReviewInputType> > {
         Name = "review"
     }),
         resolve: async context =>
     {
         var review = context.GetArgument <ProductReview>("review");
         return(await context.TryAsyncResolve(
                    async c => await productReviewRepository.AddReview(review)
                    ));
     }
         );
 }