jodd-petite/src/main/java/jodd/petite/scope/SingletonScope.java
@Override
	public void shutdown() {
		for (final BeanData beanData : instances.values()) {
			beanData.callDestroyMethods();
		}
		instances.clear();
	}
@Override
	public void shutdown() {
		for (final BeanData beanData : instances.values()) {
			beanData.callDestroyMethods();
		}
		instances.clear();
	}
Iterate all beans and invokes registered destroy methods.