public <T extends @Nullable Object> Future<T> submit(Callable<T> task) {
    return delegate().submit(task);
  }

  @Override
  public Future<?> submit(Runnable task) {
    return delegate().submit(task);
  }

  @Override
  public <T extends @Nullable Object> Future<T> submit(
      Runnable task, @ParametricNullness T result) {
    return delegate().submit(task, result);
  }

  public <T extends @Nullable Object> ListenableFuture<T> submit(Callable<T> task) {
    return delegate().submit(task);
  }

  @Override
  public ListenableFuture<?> submit(Runnable task) {
    return delegate().submit(task);
  }

  @Override
  public <T extends @Nullable Object> ListenableFuture<T> submit(
      Runnable task, @ParametricNullness T result) {
    return delegate().submit(task, result);
  }

  @Override
  public ListenableFuture<?> submit(Runnable task) {
    return (ListenableFuture<?>) super.submit(task);
  }

  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override
  public <T extends @Nullable Object> ListenableFuture<T> submit(
      Runnable task, @ParametricNullness T result) {
    return (ListenableFuture<T>) super.submit(task, result);
  }

                                    <div class="form-group row">
                                        <div class="offset-sm-2 col-sm-10">
                                            <button type="submit" class="btn btn-primary" id="submit"
                                                    name="search"
                                                    value="<la:message key="labels.crud_button_search" />">

                                    <div class="form-group row">
                                        <div class="offset-sm-2 col-sm-10">
                                            <button type="submit" class="btn btn-primary" id="submit"
                                                    name="search"
                                                    value="<la:message key="labels.crud_button_search" />">

      Future<?> possiblyIgnoredError = threadPool.submit(new Producer(q, 20));
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError1 = threadPool.submit(new Producer(q, 20));
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError2 = threadPool.submit(new Producer(q, 20));

### **4.2 WordCount**

WordCount is a simple program that counts how often a word occurs in a text file. The code builds a dataset of (String, Int) pairs called counts, and saves the dataset to a file.

The following example submits WordCount code to the Scala shell. Select an input file for the Spark WordCount example. We can use any text file as input.

- Login as user **‘spark’**.

    return delegate.awaitTermination(timeout, unit);
  }

  @Override
  public <T> ListenableFuture<T> submit(Callable<T> task) {
    Preconditions.checkNotNull(task, "task must not be null!");
    return delegate.submit(task);
  }

  @Override
  public <T> ListenableFuture<T> submit(Runnable task, T result) {
    Preconditions.checkNotNull(task, "task must not be null!");

    return delegate.awaitTermination(timeout, unit);
  }

  @Override
  public <T> ListenableFuture<T> submit(Callable<T> task) {
    Preconditions.checkNotNull(task, "task must not be null!");
    return delegate.submit(task);
  }

  @Override
  public <T> ListenableFuture<T> submit(Runnable task, T result) {
    Preconditions.checkNotNull(task, "task must not be null!");

        // When - Multiple threads accessing trees concurrently
        for (int t = 0; t < threadCount; t++) {
            final int threadId = t;
            executor.submit(() -> {
                try {
                    startLatch.await(); // Wait for all threads to be ready

                    for (int i = 0; i < opsPerThread; i++) {