return createFromEntries(entries);
  }

  public abstract Set<Entry<K, V>> createFromEntries(Entry<K, V>[] entries);

  @Override
  @SuppressWarnings("unchecked") // generic arrays make typesafety sad
  public Entry<K, V>[] createArray(int length) {
    return (Entry<K, V>[]) new Entry<?, ?>[length];
  }

  /** Returns the original element list, unchanged. */
  @Override

      return;
    }
    fail("Should get equal to incompatible class error");
  }

  /** Test proper handling where an object is not equal to one the user has said should be equal */
  public void testInvalidNotEqualsEqualObject() {
    equalsTester.addEqualityGroup(reference, notEqualObject1);
    try {
      equalsTester.testEquals();
    } catch (AssertionFailedError e) {

direction in which the March Hare was said to live.  `I've seen
hatters before,' she said to herself; `the March Hare will be
much the most interesting, and perhaps as this is May it won't be
raving mad--at least not so mad as it was in March.'  As she said
this, she looked up, and there was the Cat again, sitting on a
branch of a tree.

  `Did you say pig, or fig?' said the Cat.

         * However, we don't expose currentFuture to users, so they can't attach listeners. And the
         * Future might not even be a ListenableFuture, just a plain Future. That said, similar
         * problems can exist with methods like FutureTask.done(), not to mention slow calls to
         * Thread.interrupt() (as discussed in InterruptibleTask). At the end of the day, it's

  /** A map from wrapper types to their corresponding primitive types. */
  private static final Map<Class<?>, Class<?>> WRAPPER_TO_PRIMITIVE_TYPE;

  // Sad that we can't use a BiMap. :(

  static {
    Map<Class<?>, Class<?>> primToWrap = new LinkedHashMap<>(16);
    Map<Class<?>, Class<?>> wrapToPrim = new LinkedHashMap<>(16);

 * An immutable object that may contain a non-null reference to another object. Each instance of
 * this type either contains a non-null reference, or contains nothing (in which case we say that
 * the reference is "absent"); it is never said to "contain {@code null}".
 *
 * <p>A non-null {@code Optional<T>} reference can be used as a replacement for a nullable {@code T}
 * reference. It allows you to represent "a {@code T} that must be present" and a "a {@code T} that

   *
   * 2. `other[size] = null` is unsound. We could "fix" this by requiring callers to pass in an
   * array with a nullable element type. But probably they usually want an array with a non-nullable
   * type. That said, we could *accept* a `@Nullable T[]` (which, given that we treat arrays as
   * covariant, would still permit a plain `T[]`) and return a plain `T[]`. But of course that would

   *
   * 2. `other[size] = null` is unsound. We could "fix" this by requiring callers to pass in an
   * array with a nullable element type. But probably they usually want an array with a non-nullable
   * type. That said, we could *accept* a `@Nullable T[]` (which, given that we treat arrays as
   * covariant, would still permit a plain `T[]`) and return a plain `T[]`. But of course that would

   * result in more-than-ideal collisions for a non-uniformly distributed key space. In practice,
   * most key spaces are ANYTHING BUT uniformly distributed. A bit(i) in the input is said to
   * 'affect' a bit(j) in the output if two inputs, identical but for bit(i), will differ at output
   * bit(j) about half the time
   *

     * behavior, so it knows that `convert(a)` returns a non-nullable value, and we don't need to
     * perform even a cast, much less a runtime check.
     *
     * All that said, don't forget that everyone should call converter.convert() instead of
     * converter.apply(), anyway. If clients use only converter.convert(), then their nullness