* {@code NavigableMap}. In many cases, you may wish to override {@link
   * ForwardingNavigableMap#descendingMap} to forward to this implementation or a subclass thereof.
   *
   * <p>In particular, this map iterates over entries with repeated calls to {@link
   * NavigableMap#lowerEntry}. If a more efficient means of iteration is available, you may wish to
   * override the {@code entryIterator()} method of this class.
   *

   * override {@link #equals} to forward to this implementation.
   *
   * @since 7.0
   */
  protected boolean standardEquals(@CheckForNull Object object) {
    return Multisets.equalsImpl(this, object);
  }

  /**
   * A sensible definition of {@link #hashCode} as {@code entrySet().hashCode()} . If you override

   * A sensible, albeit inefficient, definition of {@link #remove} in terms of the {@code iterator}
   * method of {@link #entrySet}. If you override {@link #entrySet}, you may wish to override {@link
   * #remove} to forward to this implementation.
   *
   * <p>Alternately, you may wish to override {@link #remove} with {@code keySet().remove}, assuming
   * that approach would not lead to an infinite loop.
   *
   * @since 7.0
   */

   * you override either of those methods, you may wish to override {@link #equals} to forward to
   * this implementation.
   *
   * @since 7.0
   */
  protected boolean standardEquals(@CheckForNull Object object) {
    return Sets.equalsImpl(this, object);
  }

  /**
   * A sensible definition of {@link #hashCode} in terms of {@link #iterator}. If you override

 * without changing its state, so the tester needs a steady supply of fresh Iterators.
 *
 * <p>If your iterator supports modification through {@code remove()}, you may wish to override the
 * verify() method, which is called after each sequence and is guaranteed to be called
 * using the latest values obtained from {@link IteratorTester#newTargetIterator()}.
 *

 * </ul>
 *
 * <p>Static convenience methods called {@code meanOf} are also provided for users who wish to
 * calculate <i>only</i> the mean.
 *
 * <p><b>Java 8+ users:</b> If you are not using any of the variance statistics, you may wish to use
 * built-in JDK libraries instead of this class.
 *
 * @author Pete Gillin
 * @author Kevin Bourrillion
 * @since 20.0
 */

   * order. The sorting algorithm used is stable, so elements that compare as equal will stay in the
   * order in which they appear in the input.
   *
   * <p>If your data has no duplicates, or you wish to deduplicate elements, use {@code
   * ImmutableSortedSet.copyOf(elements)}; if you want a {@code List} you can use its {@code
   * asList()} view.
   *

      case HALF_DOWN:
      case HALF_UP:
      case HALF_EVEN:
        BigInteger halfSquare = sqrtFloor.pow(2).add(sqrtFloor);
        /*
         * We wish to test whether or not x <= (sqrtFloor + 0.5)^2 = halfSquare + 0.25. Since both x
         * and halfSquare are integers, this is equivalent to testing whether or not x <=
         * halfSquare.
         */

    return delegate().tailMap(fromKey);
  }

  /**
   * A sensible implementation of {@link SortedMap#keySet} in terms of the methods of {@code
   * ForwardingSortedMap}. In many cases, you may wish to override {@link
   * ForwardingSortedMap#keySet} to forward to this implementation or a subclass thereof.
   *
   * @since 15.0
   */
  protected class StandardKeySet extends Maps.SortedKeySet<K, V> {

  /**
   * Returns the next element in the iteration without advancing the iteration, according to the
   * contract of {@link PeekingIterator#peek()}.
   *
   * <p>Implementations of {@code AbstractIterator} that wish to expose this functionality should
   * implement {@code PeekingIterator}.
   */
  @ParametricNullness
  public final T peek() {
    if (!hasNext()) {
      throw new NoSuchElementException();
    }