@Override
    public void deconstruct() { }
Implement this to perform any cleanup of structures or resources allocated in the constructor,
before this component is removed.
<p>
All other calls to this component is completed before this method is called.
It will only be called once. It should block while doing cleanup tasks and return when
this class is ready for garbage collection. This method is called in reverse dependency order,
so a component will be deconstructed after any other components it is injected into.
<p>
This default implementation does nothing.
component/src/main/java/com/yahoo/component/AbstractComponent.java