@Override
    public void close() {
        log.info("Shutdown initiated, awaiting operations queue to be drained. Queue size is " + operations.size());
        drain.set(true);
        try {
            finishedDraining.await();
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }
Shutdown this feeder, waits until operations on queue is drained
vespa-feed-client-api/src/test/java/ai/vespa/feed/client/examples/JsonStreamFeederExample.java