* their users.
     *
     * However, the checker *we* use has this special knowledge about `Collection.toArray()` anyway,
     * so in our implementation code, we can rely on that. That's why the expression below
     * type-checks.
     */
    return super.toArray();
  }

  private static final long serialVersionUID = 0L;

 * in the {@link Iterators} class.
 *
 * <p><b>Java 8+ users:</b> several common uses for this class are now more comprehensively
 * addressed by the new {@link java.util.stream.Stream} library. Read the method documentation below
 * for comparisons. This class is not being deprecated, but we gently encourage you to migrate to
 * streams.
 *
 * <p><i>Performance notes:</i> Unless otherwise noted, all of the iterables produced in this class

    // TODO(kevinb): The descendingMap is never actually cached at all. Either:
    //
    // - Cache it, and annotate the field with @LazyInit.
    // - Simplify the code below, and consider eliminating the field (b/287198172), which is also
    //   set by one of the constructors.
    ImmutableSortedMap<K, V> result = descendingMap;
    if (result == null) {
      if (isEmpty()) {

    assertSame(WHATEVER, CharMatcher.none().or(WHATEVER));
  }

  // The rest of the behavior of ANY and DEFAULT will be covered in the tests for
  // the text processing methods below.

  public void testWhitespaceBreakingWhitespaceSubset() throws Exception {
    for (int c = 0; c <= Character.MAX_VALUE; c++) {
      if (breakingWhitespace().matches((char) c)) {

    assertSame(WHATEVER, CharMatcher.none().or(WHATEVER));
  }

  // The rest of the behavior of ANY and DEFAULT will be covered in the tests for
  // the text processing methods below.

  public void testWhitespaceBreakingWhitespaceSubset() throws Exception {
    for (int c = 0; c <= Character.MAX_VALUE; c++) {
      if (breakingWhitespace().matches((char) c)) {

        expectedCrc,
        actualCrcHasher);
  }

  // From RFC 3720, Section 12.1, the polynomial generator is 0x11EDC6F41.
  // We calculate the constant below by:
  //   1. Omitting the most significant bit (because it's always 1). => 0x1EDC6F41
  //   2. Flipping the bits of the constant so we can process a byte at a time. => 0x82F63B78

      return standardFirstEntry();
    }

    /*
     * We can't override lastEntry to delegate to standardLastEntry, as it would create an infinite
     * loop. Instead, we test standardLastEntry manually below.
     */

    @Override
    public @Nullable Entry<K, V> pollFirstEntry() {
      return standardPollFirstEntry();
    }

    @Override
    public @Nullable Entry<K, V> pollLastEntry() {

high enough yet--Oh! they'll do well enough; don't be particular--
Here, Bill! catch hold of this rope--Will the roof bear?--Mind
that loose slate--Oh, it's coming down!  Heads below!' (a loud
crash)--`Now, who did that?--It was Bill, I fancy--Who's to go
down the chimney?--Nay, I shan't! YOU do it!--That I won't,
then!--Bill's to go down--Here, Bill! the master says you're to
go down the chimney!'

   * supplied {@code Future} is done, unless this {@code Future} has already been cancelled or set
   * (including "set asynchronously," defined below).
   *
   * <p>If the supplied future is {@linkplain #isDone done} when this method is called and the call
   * is accepted, then this future is guaranteed to have been completed with the supplied future by

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link Collection} whose contents will never change, and which offers a few additional
 * guarantees detailed below.
 *
 * <p><b>Warning:</b> avoid <i>direct</i> usage of {@link ImmutableCollection} as a type (just as
 * with {@link Collection} itself). Prefer subtypes such as {@link ImmutableSet} or {@link