protected void handleEmbeddedOfficeDoc(DirectoryEntry dir, XHTMLContentHandler xhtml,
                                           boolean outputHtml)
            throws IOException, SAXException, TikaException {
        handleEmbeddedOfficeDoc(dir, null, xhtml, outputHtml);
    }
Handle an office document that's embedded at the POIFS level
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/AbstractPOIFSExtractor.java