0 * _

        when:
        watchingVirtualFileSystem.afterBuildFinished()
        then:
        1 * watcherRegistry.updateVfsAfterBuildFinished(_) >> watchingVirtualFileSystem.root
        0 * _

        when:
        watchingVirtualFileSystem.updateRootUnderLock { root -> nonEmptySnapshotHierarchy }

     *
     * @return the snapshot hierarchy without snapshots which can't be kept till the next build.
     */
    @CheckReturnValue
    SnapshotHierarchy updateVfsAfterBuildFinished(SnapshotHierarchy root);

    /**
     * Get statistics about the received changes.
     */
    FileWatchingStatistics getAndResetStatistics();

    /**
     * Configures debug logging.
     *

        return fileWatcherUpdater.updateVfsBeforeBuildFinished(root, maximumNumberOfWatchedHierarchies, unsupportedFileSystems);
    }

    @Override
    public SnapshotHierarchy updateVfsAfterBuildFinished(SnapshotHierarchy root) {
        return fileWatcherUpdater.updateVfsBeforeAfterFinished(root);
    }

    private static Type convertType(FileWatchEvent.ChangeType type) {
        switch (type) {

                FileWatcherRegistry watchRegistry = this.watchRegistry;
                if (watchRegistry != null) {
                    return watchRegistry.updateVfsAfterBuildFinished(currentRoot);
                } else {
                    // Drop everything if we can't watch the file system
                    return currentRoot.empty();
                }
            }));
    }