assertEquals(1, map.size());
    assertEquals(ImmutableList.of(1), map.getInstance(type));
  }

  public void testGenericArrayType() {
    @SuppressWarnings("unchecked") // Trying to test generic array
    ImmutableList<Integer>[] array =
        (ImmutableList<Integer>[]) new ImmutableList<?>[] {ImmutableList.of(1)};

   */
  protected abstract Iterable<? extends Stimulus<E, ? super I>> getStimulusValues();

  /**
   * Returns a new target iterator each time it's called. This is the iterator you are trying to
   * test. This must return an Iterator that returns the expected elements passed to the constructor
   * in the given order. Warning: it is not enough to simply pull multiple iterators from the same

  //      since, after all, this class is also a reentrant mutual exclusion lock!?

  /*
   * One of the key challenges of this class is to prevent lost signals, while trying hard to
   * minimize unnecessary signals. One simple and correct algorithm is to signal some other waiter
   * with a satisfied guard (if one exists) whenever any thread occupying the monitor exits the

name: Feature Enhancement Request
description: I want to make an existing feature better
labels: ["type=enhancement"]
body:
  - type: markdown
    attributes:
      value: >
        Filing feature requests is one of the most popular ways to contribute to Guava.


        Be aware, though: most feature requests are not accepted, even if they're suggested by
        a full-time Guava team member. [Feedback](https://stackoverflow.com/a/4543114) from our

    assertEquals(1, map.size());
    assertEquals(ImmutableList.of(1), map.getInstance(type));
  }

  public void testGenericArrayType() {
    @SuppressWarnings("unchecked") // Trying to test generic array
    ImmutableList<Integer>[] array =
        (ImmutableList<Integer>[]) new ImmutableList<?>[] {ImmutableList.of(1)};

    assertEquals(1, map.size());
    assertEquals(ImmutableList.of(1), map.getInstance(type));
  }

  public void testGenericArrayType() {
    @SuppressWarnings("unchecked") // Trying to test generic array
    ImmutableList<Integer>[] array =
        (ImmutableList<Integer>[]) new ImmutableList<?>[] {ImmutableList.of(1)};

  private static final class Failure {
    static final Failure FALLBACK_INSTANCE =
        new Failure(
            new Throwable("Failure occurred while trying to finish a future.") {
              @Override
              public synchronized Throwable fillInStackTrace() {
                return this; // no stack trace
              }
            });

   */
  protected abstract Iterable<? extends Stimulus<E, ? super I>> getStimulusValues();

  /**
   * Returns a new target iterator each time it's called. This is the iterator you are trying to
   * test. This must return an Iterator that returns the expected elements passed to the constructor
   * in the given order. Warning: it is not enough to simply pull multiple iterators from the same

  public void testTransform_StackOverflow() throws Exception {
    {
      /*
       * Initialize all relevant classes before running the test, which may otherwise poison any
       * classes it is trying to load during its stack overflow.
       */
      SettableFuture<Object> root = SettableFuture.create();
      ListenableFuture<Object> unused = transform(root, identity(), directExecutor());
      root.set("foo");

 * existing users, but it can't *fix* existing users because any users who needed
 * `Function<@Nullable A, @Nullable B>` already had to find a workaround. Still, there is a *ton* of
 * fallout from trying to switch. I would be shocked if the switch would offer benefits to anywhere
 * near enough users to justify the costs.
 *
 * Fortunately, if anyone does want to use a Converter as a `Function<@Nullable A, @Nullable B>`,