52,52c52,52
< 	private QuadTree  _theQuadTree;
---
> 	private transient QuadTree  _theQuadTree;
70,70c70,70
< 		if (!fFigures.contains(figure)) {
---
> 		if (!containsFigure(figure)) {
158,158c158,158
< 		if (fFigures.contains(figure)) {
---
> 		if (containsFigure(figure)) {
210,210c210,210
< 		if (fFigures.contains(figure)) {
---
> 		if (containsFigure(figure)) {
225,225c225,225
< 		if (fFigures.contains(figure)) {
---
> 		if (containsFigure(figure)) {
253,253c253,253
< 		if (fFigures.contains(figure)) {
---
> 		if (containsFigure(figure)) {
311,311c311,311
< 		if (!fFigures.contains(figure)) {
---
> 		if (!containsFigure(figure)) {
365a366,368
>      * The enumeration is a snapshot of the current contained figures
>      * and is not a "live" enumeration and does not take subsequent
>      * changes of the CompositeFigure into account.
414a418,424
> 	 * Check whether a given figure is a child figure of this CompositeFigure.
> 	 */
> 	public boolean containsFigure(Figure checkFigure) {
> 		return fFigures.contains(checkFigure);
> 	}
> 
>     /**