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

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

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

      Predicate<E> combinedPredicate = Predicates.and(filtered.predicate, predicate);
      return new FilteredSet<>((Set<E>) filtered.unfiltered, combinedPredicate);
    }

    return new FilteredSet<>(checkNotNull(unfiltered), checkNotNull(predicate));
  }

  /**
   * Returns the elements of a {@code SortedSet}, {@code unfiltered}, that satisfy a predicate. The

   * {@code predicate}.
   *
   * @since 2.0
   */
  public static <T extends @Nullable Object> int indexOf(
      Iterator<T> iterator, Predicate<? super T> predicate) {
    checkNotNull(predicate, "predicate");
    for (int i = 0; iterator.hasNext(); i++) {
      T current = iterator.next();
      if (predicate.apply(current)) {
        return i;
      }
    }

      SetMultimap<K, V> filterFiltered(
          FilteredSetMultimap<K, V> multimap, Predicate<? super Entry<K, V>> entryPredicate) {
    Predicate<Entry<K, V>> predicate =
        Predicates.<Entry<K, V>>and(multimap.entryPredicate(), entryPredicate);
    return new FilteredEntrySetMultimap<>(multimap.unfiltered(), predicate);
  }

  static boolean equalsImpl(Multimap<?, ?> multimap, @Nullable Object object) {

      SetMultimap<K, V> filterFiltered(
          FilteredSetMultimap<K, V> multimap, Predicate<? super Entry<K, V>> entryPredicate) {
    Predicate<Entry<K, V>> predicate =
        Predicates.<Entry<K, V>>and(multimap.entryPredicate(), entryPredicate);
    return new FilteredEntrySetMultimap<>(multimap.unfiltered(), predicate);
  }

  static boolean equalsImpl(Multimap<?, ?> multimap, @Nullable Object object) {

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

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

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

  /** Implementation of {@link #forPredicate(Predicate)}. */
  private static final class ForPredicate extends CharMatcher {

    private final Predicate<? super Character> predicate;

    ForPredicate(Predicate<? super Character> predicate) {
      this.predicate = checkNotNull(predicate);
    }

    @Override
    public boolean matches(char c) {
      return predicate.apply(c);
    }

    @Override

			}
		}
	}
}

type predicate struct {
	f    func(r rune) bool
	name string
}

var isSpace = predicate{unicode.IsSpace, "IsSpace"}
var isDigit = predicate{unicode.IsDigit, "IsDigit"}
var isUpper = predicate{unicode.IsUpper, "IsUpper"}
var isValidRune = predicate{
	func(r rune) bool {
		return r != utf8.RuneError
	},
	"IsValidRune",
}