xstream.alias("option", Option.class);
xstream.alias("problem", SBMLError.class);
xstream.alias("location", Location.class);
xstream.alias("detail", Detail.class);
// xstream.registerConverter(new MessageConverter(), XStream.PRIORITY_VERY_HIGH);
xstream.registerLocalConverter(SBMLError.class, "message", new MessageConverter("message"));
xstream.registerLocalConverter(SBMLError.class, "shortmessage", new MessageConverter("shortmessage"));
xstream.alias("message", Message.class);
xstream.alias("shortmessage", Message.class);
xstream.addImplicitCollection(SBMLErrorLog.class, "options",