/** setter for the importance (priority) label of a node
* @param node a GSSElementGraphNode
* @param element the Element of the GSSElementGraphNode
*/
protected void setNodeImportance(final GSSElementGraphNode node, final Element element) {
cacheManager.addCacheChangedListener(new ICacheChangedListener() {
@Override
public void changed() {
updateNodeImportance(node, element);