/**
* Obtain the ClusteringTopComponent instance. Never call {@link #getDefault} directly!
*/
public static synchronized ClusteringTopComponent findInstance() {
TopComponent win = WindowManager.getDefault().findTopComponent(PREFERRED_ID);
if (win == null) {
Logger.getLogger(ClusteringTopComponent.class.getName()).warning(
"Cannot find " + PREFERRED_ID + " component. It will not be located properly in the window system.");
return getDefault();
}