presto-main/src/main/java/io/prestosql/util/FinalizerService.java/FinalizerService/destroy
class FinalizerService:    @PreDestroy
    public synchronized void destroy()
    {
        if (finalizerTask != null) {
            finalizerTask.cancel(true);
            finalizerTask = null;
        }
        if (executor != null) {
            executor.shutdownNow();
            executor = null;
        }
    }