if ((content instanceof StreamSource || content instanceof SAXSource) && !(content instanceof StringSource) && !(content instanceof BytesSource) && !(content instanceof ResourceSource)) { content = new StringSource(src); }
    public void writeExternal(ObjectOutput out) throws IOException {        try {            out.writeObject(attachments);            out.writeObject(properties);            String src = transformer.toString(content);            out.writeObject(src);        } catch (TransformerException e) {            throw (IOException) new IOException("Could not transform content to string").initCause(e);        }    }