protected static SimulationRegistry instance;
private Map<Class<? extends Node>, ActivitySimulator> simulators = new HashMap<Class<? extends Node>, ActivitySimulator>();
protected SimulationRegistry() {
simulators.put(StartNode.class, new StartEventSimulator());
simulators.put(EndNode.class, new EndEventSimulator());
simulators.put(HumanTaskNode.class, new HumanTaskActivitySimulator());
simulators.put(Split.class, new GatewaySimulator());
simulators.put(Join.class, new GatewaySimulator());
simulators.put(EventNode.class, new EventSimulator());