<T extends @Nullable Object> Predicate<T> withNarrowedType() {
      return (Predicate<T>) this;
    }
  }

  /**
   * @see Predicates#not(Predicate)
   */
  private static final class NotPredicate<T extends @Nullable Object>
      implements Predicate<T>, Serializable {
    final Predicate<T> predicate;

    NotPredicate(Predicate<T> predicate) {
      this.predicate = checkNotNull(predicate);
    }

  }

  public void testAnd_listDefensivelyCopied() {
    List<Predicate<Object>> list = new ArrayList<>();
    Predicate<Object> predicate = Predicates.and(list);
    assertTrue(predicate.apply(1));
    list.add(Predicates.alwaysFalse());
    assertTrue(predicate.apply(1));
  }

  public void testAnd_iterableDefensivelyCopied() {
    List<Predicate<Object>> list = new ArrayList<>();

    List<String> list = new ArrayList<>();
    Predicate<String> predicate = equalTo("pants");

    assertFalse(any(list, predicate));
    list.add("cool");
    assertFalse(any(list, predicate));
    list.add("pants");
    assertTrue(any(list, predicate));
  }

  public void testAll() {
    List<String> list = new ArrayList<>();
    Predicate<String> predicate = equalTo("cool");

  }

  public void testAnd_listDefensivelyCopied() {
    List<Predicate<Object>> list = new ArrayList<>();
    Predicate<Object> predicate = Predicates.and(list);
    assertTrue(predicate.apply(1));
    list.add(Predicates.alwaysFalse());
    assertTrue(predicate.apply(1));
  }

  public void testAnd_iterableDefensivelyCopied() {
    List<Predicate<Object>> list = new ArrayList<>();

    final Collection<E> unfiltered;
    final Predicate<? super E> predicate;

    FilteredCollection(Collection<E> unfiltered, Predicate<? super E> predicate) {
      this.unfiltered = unfiltered;
      this.predicate = predicate;
    }

    FilteredCollection<E> createCombined(Predicate<? super E> newPredicate) {
      return new FilteredCollection<>(unfiltered, Predicates.and(predicate, newPredicate));
    }

    @Override

      return ((Collection<T>) removeFrom).removeIf(predicate);
    }
    return Iterators.removeIf(removeFrom.iterator(), predicate);
  }

  /** Removes and returns the first matching element, or returns {@code null} if there is none. */
  static <T extends @Nullable Object> @Nullable T removeFirstMatching(
      Iterable<T> removeFrom, Predicate<? super T> predicate) {
    checkNotNull(predicate);

      Iterable<T> iterable, Predicate<? super T> predicate) {
    return Iterators.find(iterable.iterator(), predicate);
  }

  /**
   * Returns the first element in {@code iterable} that satisfies the given predicate, or {@code
   * defaultValue} if none found. Note that this can usually be handled more naturally using {@code
   * tryFind(iterable, predicate).or(defaultValue)}.
   *

    Iterable<A> aIterable = ImmutableList.of();
    Iterable<B> bIterable = ImmutableList.of();

    Predicate<X> xPredicate = Predicates.alwaysTrue();
    Predicate<Y> yPredicate = Predicates.alwaysTrue();

    FluentIterable<?> unused =
        FluentIterable.concat(aIterable, bIterable).filter(xPredicate).filter(yPredicate);

    /* The following fails to compile:
     *

  }

  /**
   * Waits until the given predicate returns true, invoking the garbage collector as necessary to
   * try to ensure that this will happen.
   *
   * @throws RuntimeException if timed out or interrupted while waiting
   */
  @SuppressWarnings("removal") // b/260137033
  public static void awaitDone(FinalizationPredicate predicate) {
    if (predicate.isDone()) {
      return;
    }

    private final Predicate<T> predicate;

    private PredicateFunction(Predicate<T> predicate) {
      this.predicate = checkNotNull(predicate);
    }

    @Override
    public Boolean apply(@ParametricNullness T t) {
      return predicate.apply(t);
    }

    @Override
    public boolean equals(@Nullable Object obj) {
      if (obj instanceof PredicateFunction) {