protected void parse(POIFSFileSystem filesystem, XHTMLContentHandler xhtml, Locale locale)
            throws IOException, SAXException, TikaException {
        parse(filesystem.getRoot(), xhtml, locale);
    }
Extracts text from an Excel Workbook writing the extracted content
to the specified {@link Appendable}.

@param filesystem POI file system
@throws IOException if an error occurs processing the workbook
                    or writing the extracted content
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/main/java/org/apache/tika/parser/microsoft/ExcelExtractor.java