private void handleEmbedded(TikaInputStream tis, Metadata embeddedMetadata,
                                XHTMLContentHandler xhtml,
                                EmbeddedDocumentExtractor embeddedDocumentExtractor)
            throws IOException, SAXException {
        if (embeddedDocumentExtractor.shouldParseEmbedded(embeddedMetadata)) {
            embeddedDocumentExtractor.parseEmbedded(tis, xhtml, embeddedMetadata, true);
        }
    }
All iWork 13 files contain this, so we can detect based on it
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-apple-module/src/main/java/org/apache/tika/parser/iwork/iwana/IWork13PackageParser.java