final PDDocumentNameDictionary namesDictionary = new PDDocumentNameDictionary(document.getDocumentCatalog());
        final PDEmbeddedFilesNameTreeNode efTree = namesDictionary.getEmbeddedFiles();
        if (efTree == null) {
            return;
        }

        try {
            final Map<String, PDComplexFileSpecification> embeddedFileNames = efTree.getNames();