when:
        allowFileSystemAccess(true)
        def snapshot = read(someFile)
        then:
        assertIsFileSnapshot(snapshot, someFile)

        when:
        allowFileSystemAccess(false)
        fileSystemAccess.write([someFile.absolutePath]) {
            someFile << "Updated"
        }

        and:
        allowFileSystemAccess(true)
        snapshot = read(someFile)

        def dir = temporaryFolder.createDir("some/deep/hierarchy")
        (1..1000).each {
            def subdir = dir.file(it)
            subdir.file("in-dir.txt").createFile()
        }

        allowFileSystemAccess(true)
        read(dir)
        def executorService = Executors.newFixedThreadPool(100)

        when:
        (1..1000).each { num ->
            executorService.submit({

        fileHasher,
        new StringInterner(),
        fileSystem::stat,
        TestFiles.virtualFileSystem(),
        updateListener,
        statisticsCollector
    )

    void allowFileSystemAccess(boolean allow) {
        fileHasher.allowHashing(allow)
        fileSystem.allowStat(allow)
    }

    FileSystemLocationSnapshot read(File file) {
        return fileSystemAccess.read(file.absolutePath)
    }