SMapImpl attrs = new SMapImpl();
attrs.put(null, "version", "2005-1");
String lang = epub.getDCMetadata("language");
if (lang != null)
attrs.put(null, "xml:lang", lang);
ser.startElement(ncxns, "ncx", attrs, true);
ser.newLine();
ser.startElement(ncxns, "head", null, false);
ser.newLine();
attrs = new SMapImpl();
attrs.put(null, "name", "dtb:uid");