private void parseEmbedded(DirectoryEntry dir, TikaInputStream tis, XHTMLContentHandler xhtml,
                               Metadata metadata, boolean outputHtml) throws IOException,
            SAXException {
        if (!embeddedDocumentUtil.shouldParseEmbedded(metadata)) {
            return;
        }
        if (dir.getStorageClsid() != null) {
            metadata.set(Office.EMBEDDED_STORAGE_CLASS_ID,
                    dir.getStorageClsid().toString());
        }
        embeddedDocumentUtil.parseEmbedded(tis, xhtml, metadata, 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