/**
     * Returns the canonical string representation of this entry, defined as follows. If the count
     * for this entry is one, this is simply the string representation of the corresponding element.
     * Otherwise, it is the string representation of the element, followed by the three characters
     * {@code " x "} (space, letter x, space), followed by the count.
     */
    @Override
    String toString();
  }

 * equals</i>. That is, {@code a.compareTo(b)} or {@code comparator.compare(a, b)} should equal zero
 * <i>if and only if</i> {@code a.equals(b)}. If this advice is not followed, the resulting map will
 * not correctly obey its specification.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *

   *
   * <p>The returned {@code Iterable} can be iterated over multiple times. Every iterator will
   * compute its next element on the fly. It is thus possible to limit the traversal to a certain
   * number of nodes as follows:
   *
   * <pre>{@code
   * Iterables.limit(Traverser.forGraph(graph).breadthFirst(node), maxNumberOfNodes);
   * }</pre>
   *

   * <p><i>Notes:</i> This is an implementation of the algorithm for Lexicographical Permutations
   * Generation, described in Knuth's "The Art of Computer Programming", Volume 4, Chapter 7,
   * Section 7.2.1.2. The iteration order follows the lexicographical order. This means that the
   * first permutation will be in ascending order, and the last will be in descending order.
   *

   * concurrently updating.
   */
  public void reset() {
    internalReset(0L);
  }

  /**
   * Equivalent in effect to {@link #sum} followed by {@link #reset}. This method may apply for
   * example during quiescent points between multithreaded computations. If there are updates
   * concurrent with this method, the returned value is not guaranteed to be the final

  private static final int TO_BYTE_ARRAY_DEQUE_SIZE = 20;

  /**
   * Returns a byte array containing the bytes from the buffers already in {@code bufs} (which have
   * a total combined length of {@code totalLen} bytes) followed by all bytes remaining in the given
   * input stream.
   */
  private static byte[] toByteArrayInternal(InputStream in, Queue<byte[]> bufs, int totalLen)
      throws IOException {

    a >>= aTwos; // divide out all 2s
    int bTwos = Integer.numberOfTrailingZeros(b);
    b >>= bTwos; // divide out all 2s
    while (a != b) { // both a, b are odd
      // The key to the binary GCD algorithm is as follows:
      // Both a and b are odd. Assume a > b; then gcd(a - b, b) = gcd(a, b).
      // But in gcd(a - b, b), a - b is even and b is odd, so we can divide out powers of two.

    try {
      Ordering.explicit(1, 2, 3, 4, 2);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  // A more limited test than the one that follows, but this one uses the
  // actual public API.
  @J2ktIncompatible // Ordering.arbitrary
  public void testArbitrary_withoutCollisions() {
    List<Object> list = Lists.newArrayList();
    for (int i = 0; i < 50; i++) {

    try {
      Ordering.explicit(1, 2, 3, 4, 2);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  // A more limited test than the one that follows, but this one uses the
  // actual public API.
  @J2ktIncompatible // Ordering.arbitrary
  public void testArbitrary_withoutCollisions() {
    List<Object> list = Lists.newArrayList();
    for (int i = 0; i < 50; i++) {

 * equals</i>. That is, {@code a.compareTo(b)} or {@code comparator.compare(a, b)} should equal zero
 * <i>if and only if</i> {@code a.equals(b)}. If this advice is not followed, the resulting
 * collection will not correctly obey its specification.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.