public ProductMutation(ProductReviewManager reviewRepository) { FieldAsync <ProductReviewGraph>( "createReview", arguments: new QueryArguments( new QueryArgument <NonNullGraphType <ProductReviewInputGraph> > { Name = "review" }), resolve: async context => { var review = context.GetArgument <ProductReview>("review"); return(await context.TryAsyncResolve( async c => await reviewRepository.AddReview(review))); }); }