@Override
    public void init() {
        beforeHandoverMode = false;
        clientClosed = false;
        singleThreaded = new Object();
        dataListListenerStack = new ArrayDeque<>();
        networkIsInitialized = false;
        isInitialized  = true;
    }
Do per instance initialization. If overriding this in a subclass, not
invoking it in the subclass' implementation will most likely cause the
rendering to fail with an exception.
container-core/src/main/java/com/yahoo/processing/rendering/AsynchronousSectionedRenderer.java