when:
        def filtered = FileSystemSnapshotFilter.filterSnapshot(snapshottingFilter(include("**/*File*")).asSnapshotPredicate, unfiltered)

        then:
        filtered.is(unfiltered)
    }

    private Set<File> filteredPaths(FileSystemSnapshot unfiltered, PatternSet patterns) {
        def result = [] as Set
        def filtered = FileSystemSnapshotFilter.filterSnapshot(snapshottingFilter(patterns).asSnapshotPredicate, unfiltered)

        Map<String, FileSystemLocationSnapshot> previousIndex = indexByAbsolutePath(previous);
        return filterSnapshot(current, (currentSnapshot, isRoot) ->
            // Include only outputs that we already considered outputs after the previous execution
            previousIndex.containsKey(currentSnapshot.getAbsolutePath())
        );

            return Optional.of(read(location));
        } else {
            FileSystemSnapshot filteredSnapshot = readSnapshotFromLocation(location,
                snapshot -> FileSystemSnapshotFilter.filterSnapshot(filter.getAsSnapshotPredicate(), snapshot),
                () -> {
                    FileSystemLocationSnapshot snapshot = snapshot(location, filter);
                    return snapshot.getType() == FileType.Directory

public class FileSystemSnapshotFilter {

    private FileSystemSnapshotFilter() {
    }

    public static FileSystemSnapshot filterSnapshot(SnapshottingFilter.FileSystemSnapshotPredicate predicate, FileSystemSnapshot unfiltered) {
        DirectorySnapshotBuilder builder = MerkleDirectorySnapshotBuilder.noSortingRequired();