@Override
    public void start() {
        executor = Executors.newFixedThreadPool(1, ThreadUtils.createThreadFactory(
                this.getClass().getSimpleName() + "-%d", false));
    }
Implementation of OffsetBackingStore that doesn't actually persist any data. To ensure this
behaves similarly to a real backing store, operations are executed asynchronously on a
background thread.
connect/runtime/src/main/java/org/apache/kafka/connect/storage/MemoryOffsetBackingStore.java