Example how to work with access control lists in the MockFileSystem.
In order to be able to support simulating access restrictions, the MockFileSystem provides a IAccessControlStrategy
that can be set via MockFileSystem.WithAccessControlStrategy(...) which simulates access restrictions.
The included default implementation uses a callback to determine whether or not to grant access to a given file or directory.
The example shows how to implement a custom strategy and provides a test where access to one path is granted
and access to a second path is denied. In the second case an IOException is thrown when trying to
read the file.