* support double buffering has no effect.
* @param enable if true, double buffering will be enabled
* @throws IllegalStateException if the Canvas3D is already attached to a Container
*/
public final void setDoubleBufferEnabled(boolean enable) {
if (canvas != null) throw new RestrictedAccessException();
if (isDoubleBufferAvailable() || !enable) caps.setDoubleBuffered(enable);
}