* @param writer the writer to append extracted text to
     */
    protected void extractEmbeddedDocuments(final PDDocument document, final StringWriter writer) {
        final PDDocumentNameDictionary namesDictionary = new PDDocumentNameDictionary(document.getDocumentCatalog());
        final PDEmbeddedFilesNameTreeNode efTree = namesDictionary.getEmbeddedFiles();
        if (efTree == null) {
            return;
        }