private MediaType processZipStream(ZipInputStream zipStream, Metadata metadata,
                                       XHTMLContentHandler xhtml, ParseContext parseContext)
            throws TikaException, IOException, SAXException {
        MediaType type = null;
        ZipEntry entry = zipStream.getNextEntry();
        EmbeddedDocumentExtractor embeddedDocumentExtractor =
                EmbeddedDocumentUtil.getEmbeddedDocumentExtractor(parseContext);
        while (entry != null) {
            if (type == null) {
                type = IWork13DocumentType.detectIfPossible(entry);
            }

            try (TemporaryResources tmp = new TemporaryResources()) {
                TikaInputStream tis = TikaInputStream.get(zipStream, tmp, new Metadata());
                processZipEntry(entry, tis, metadata, xhtml, parseContext, embeddedDocumentExtractor);
            }
            entry = zipStream.getNextEntry();
        }
        if (type == null) {
            type = IWork13DocumentType.UNKNOWN13.getType();
        }
        return type;
    }
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