}

    private File getInProgressMarkerFile(File file) {
        return new File(file.getParent(), file.getName() + IN_PROGRESS_MARKER_FILE_SUFFIX);
    }

    private boolean isInProgressMarkerFile(File file) {
        return hasExtension(file, IN_PROGRESS_MARKER_FILE_SUFFIX);
    }

    private boolean isInProgressFile(File file) {
        return getInProgressMarkerFile(file).exists();
    }