private List _stepSizeControllers() {
if (_workspace.getVersion() != _stepSizeControllersVersion) {
// Construct the list.
_stepSizeControllers.clear();
CompositeEntity container = (CompositeEntity) getContainer();
Iterator actors = container.deepEntityList().iterator();
while (actors.hasNext()) {
Object actor = actors.next();
if (actor instanceof ContinuousStepSizeController) {
_stepSizeControllers.add(actor);
} else if ((actor instanceof CompositeActor)