Product recommendation sample

[Ivanidzo4ka]

I would suggest to create const MaxId
private const long MaxId = 262111;
and use it across whole file https://github.com/dotnet/machinelearning-samples/blob/master/samples/csharp/getting-started/MatrixFactorization_ProductRecommendation/ProductRecommender/Program.cs and add comment what it should be (maximum id value in file +1).
Any Id which is above or equal to that value would be ignored.
Otherwise users will just bring their dataset and would be upset that it doesn't work like here: dotnet/machinelearning#2488

[wschin]

As dotnet/machinelearning#2488 had been fixed, may we close this issue?

[prathyusha12345]

Sure @wschin