CountDownLatch tasksFinished = new CountDownLatch(nTasks);
    for (int i = 0; i < nTasks; i++) {
      String s = "a" + i;
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError =
          threadPool.submit(
              new Runnable() {
                @Override
                public void run() {
                  cache.getUnchecked(s);

      AbstractFuture<String> future = new AbstractFuture<String>() {};
      currentFuture.set(future);
      for (Callable<?> task : allTasks) {
        @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
        Future<?> possiblyIgnoredError = executor.submit(task);
      }
      awaitUnchecked(barrier);
      assertThat(future.isDone()).isTrue();
      // inspect state and ensure it is correct!