((ChsRootEditPart) main.getViewer().getRootEditPart().
getChildren().get(0)).getModel();
BufferedWriter xmlFile =
new BufferedWriter(new FileWriter(fileName));
GraphMLWriter writer = new GraphMLWriter();
xmlFile.write(writer.writeXMLFile(root).toString());
xmlFile.close();
// mark save location in commandstack
main.getEditDomain().getCommandStack().markSaveLocation();
}