*   <li>The performance of using the associated {@code Builder} class can be assumed to be no
 *       worse, and possibly better, than creating a mutable collection and copying it.
 *   <li>Implementations generally do not cache hash codes. If your element or key type has a slow
 *       {@code hashCode} implementation, it should cache it itself.
 * </ul>
 *
 * <h4>Example usage</h4>
 *
 * <pre>{@code
 * class Foo {

 *   <li>The performance of using the associated {@code Builder} class can be assumed to be no
 *       worse, and possibly better, than creating a mutable collection and copying it.
 *   <li>Implementations generally do not cache hash codes. If your element or key type has a slow
 *       {@code hashCode} implementation, it should cache it itself.
 * </ul>
 *
 * <h4>Example usage</h4>
 *
 * <pre>{@code
 * class Foo {

   *       y}, if {@code equivalent(x, y)}, then {@code hash(x) == hash(y)}. It is <i>not</i>
   *       necessary that the hash be distributable across <i>inequivalence</i>. If {@code
   *       equivalence(x, y)} is false, {@code hash(x) == hash(y)} may still be true.
   *   <li>{@code hash(null)} is {@code 0}.
   * </ul>
   */
  public final int hash(@CheckForNull T t) {
    if (t == null) {
      return 0;
    }

   *       y}, if {@code equivalent(x, y)}, then {@code hash(x) == hash(y)}. It is <i>not</i>
   *       necessary that the hash be distributable across <i>inequivalence</i>. If {@code
   *       equivalence(x, y)} is false, {@code hash(x) == hash(y)} may still be true.
   *   <li>{@code hash(null)} is {@code 0}.
   * </ul>
   */
  public final int hash(@CheckForNull T t) {
    if (t == null) {
      return 0;
    }

 * amortized) constant time operations. Expected in the hashtable sense (depends on the hash
 * function doing a good job of distributing the elements to the buckets to a distribution not far
 * from uniform), and amortized since some operations can trigger a hash table resize.
 *
 * <p>As compared with {@link java.util.LinkedHashMap}, this structure places significantly reduced

     * ImmutableSortedMultiset#orderedBy(Comparator)}.
     */
    @SuppressWarnings("unchecked")
    public Builder(Comparator<? super E> comparator) {
      super(true); // doesn't allocate hash table in supertype
      this.comparator = checkNotNull(comparator);
      this.elements = (E[]) new Object[ImmutableCollection.Builder.DEFAULT_INITIAL_CAPACITY];