/** 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);
    }

  /** 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);
    }