public void writeExternal(Element element) throws WriteExternalException { saveExpandedPaths(); for (String subId : myReadTreeState.keySet()) { TreeState treeState = myReadTreeState.get(subId); Element subPane = new Element(ELEMENT_SUBPANE); if (subId != null) { subPane.setAttribute(ATTRIBUTE_SUBID, subId); } treeState.writeExternal(subPane); element.addContent(subPane); } }