}
  }

  private static Iterator<Integer> iterateOver(int... values) {
    // Note: Ints.asList's iterator does not support remove which we need for testing.
    return new ArrayList<>(Ints.asList(values)).iterator();
  }

  public void testElementsEqual() {
    Iterable<?> a;
    Iterable<?> b;

    // Base case.

   *
   * @since 12.0
   */
  public static class Builder<E> extends ImmutableMultiset.Builder<E> {
    /*
     * We keep an array of elements and counts.  Periodically -- when we need more room in the
     * array, or when we're building, or the like -- we sort, deduplicate, and combine the counts.
     * Negative counts indicate a setCount operation with ~counts[i].
     */

         * Don't store a new Iterator until we know the user can't remove() the last returned
         * element anymore. Otherwise, when we remove from the old iterator, we may be invalidating
         * the new one. The result is a ConcurrentModificationException or other bad behavior.
         *
         * (If we decide that we really, really hate allocating two Iterators per cycle instead of

 *
 * <p><b>For users targeting Android API level 24 or higher:</b> This class will eventually
 * implement {@code BiPredicate<T, T>} (as it does in the main Guava artifact), but we currently
 * target a lower API level. In the meantime, if you have support for method references you can use
 * an equivalence as a bi-predicate like this: {@code myEquivalence::equivalent}.
 *
 * @author Bob Lee