final class CurrentThreadExecuto implements CompletionService Override

final class CurrentThreadExecutor implements CompletionService {
        @Override
        public Future submit(Callable task) {
          return null;
        }

        @Override
        public Future submit(Runnable task, Object result) {
          return null;
        }

        @Override
        public Future take() throws InterruptedException {
          return null;
        }

        @Override
        public Future poll() {
          return null;
        }

        @Override
        public Future poll(long timeout, TimeUnit unit) throws InterruptedException {
          return null;
        }

        {
      }}