for (int i=0; i<columnCount; i++) { TreeColumn column = columns [i]; if (!column.isDisposed ()) column.releaseResources (); } columns = null;
void releaseWidget () {	for (int i=0; i<columnCount; i++) {		TreeColumn column = columns [i];		if (!column.isDisposed ()) column.releaseResources ();	}	columns = null;	for (int i=0; i<items.length; i++) {		TreeItem item = items [i];		if (item != null && !item.isDisposed ()) {			item.releaseResources ();		}	}	items = null;	super.releaseWidget ();}