serializer.setProperty("http://xmlpull.org/v1/doc/properties.html#serializer-line-separator", "\n");
        serializer.setOutput(writer);
        serializer.startDocument(coreExtensions.getModelEncoding(), null);
        writeCoreExtensions(coreExtensions, "extensions", serializer);
        serializer.endDocument();
    } // -- void write( Writer, CoreExtensions )

    /**