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