<!-- This template is useful to build consensus about whether work should be done, and if so, the high-level shape of how it should be approached. Use this before fixating on a particular implementation. --> ## Summary I'd like to add two missing methods for VirtualPathProvider. ## Detailed design The PR is created [here](https://github.com/dotnet/systemweb-adapters/pull/562), all pipelines pass.