registerWatchableHierarchies([watchableHierarchy])
        def subDirInRootDir = watchableHierarchy.file("some/path").createDir()
        def snapshotInRootDir = snapshotDirectory(subDirInRootDir)

        when:
        addSnapshot(snapshotInRootDir)
        then:
        1 * watcher.startWatching({ equalIgnoringOrder(it, [watchableHierarchy]) })
        0 * _

        when:

    def "watchers are stopped when removing the last watched snapshot"() {
        def rootDir = file("root").createDir()
        ["first", "second", "third"].collect { rootDir.createFile(it) }
        def rootDirSnapshot = snapshotDirectory(rootDir)

        when:
        registerWatchableHierarchies([rootDir])
        addSnapshot(rootDirSnapshot)
        then:
        1 * watcher.startWatching({ equalIgnoringOrder(it, [rootDir]) })

        0 * _
    }

    TestFile file(Object... path) {
        temporaryFolder.testDirectory.file(path)
    }

    DirectorySnapshot snapshotDirectory(File directory) {
        directorySnapshotter.snapshot(directory.absolutePath, null, [:]) {} as DirectorySnapshot
    }

    void addSnapshot(FileSystemLocationSnapshot snapshot) {