return CollectCollectors.toImmutableSortedMap(
        comparator, keyFunction, valueFunction, mergeFunction);
  }

  /*
   * TODO(kevinb): Confirm that ImmutableSortedMap is faster to construct and
   * uses less memory than TreeMap; then say so in the class Javadoc.
   */
  private static final Comparator<?> NATURAL_ORDER = Ordering.natural();

  private static final ImmutableSortedMap<Comparable<?>, Object> NATURAL_EMPTY_MAP =

   * any of the public methods of ListenableFuture.
   */
  interface Trusted<V extends @Nullable Object> extends ListenableFuture<V> {}

  /**
   * A less abstract subclass of AbstractFuture. This can be used to optimize setFuture by ensuring
   * that {@link #get} calls exactly the implementation of {@link AbstractFuture#get}.
   */

          int foundIndex) {
        return LAST_PRESENT.resultIndex(comparator, key, list, foundIndex) + 1;
      }
    },
    /**
     * Return the index of the last list element that compares as less than the key, or {@code -1}
     * if there is no such element.
     */
    LAST_BEFORE {
      @Override
      public <E extends @Nullable Object> int resultIndex(
          Comparator<? super E> comparator,

   * Contention and/or table collisions are indicated by failed
   * CASes when performing an update operation (see method
   * retryUpdate). Upon a collision, if the table size is less than
   * the capacity, it is doubled in size unless some other thread
   * holds the lock. If a hashed slot is empty, and lock is
   * available, a new Cell is created. Otherwise, if the slot

        || (stimuli.length >= 5 && removes > 2)) {
      // removes are the most expensive thing to test, since they often throw exceptions with stack
      // traces, so we test them a bit less aggressively
      return;
    }

    MultiExceptionListIterator reference = new MultiExceptionListIterator(expectedElements);
    I target = newTargetIterator();
    for (int i = 0; i < stimuli.length; i++) {

     * traverse. When nodes would otherwise be changed, new nodes are created to replace them. This
     * works well for hash tables since the bin lists tend to be short. (The average length is less
     * than two.)
     *
     * Read operations can thus proceed without locking, but rely on selected uses of volatiles to
     * ensure that completed write operations performed by other threads are noticed. For most

  @CheckForNull
  public abstract C next(C value);

  /**
   * Returns the unique greatest value of type {@code C} that is less than {@code value}, or {@code
   * null} if none exists. Inverse operation to {@link #next}.
   *
   * @param value any value of type {@code C}
   * @return the greatest value less than {@code value}, or {@code null} if {@code value} is {@code
   *     minValue()}
   */
  @CheckForNull

   * Math#min(float, float)}.
   *
   * @param array a <i>nonempty</i> array of {@code float} values
   * @return the value present in {@code array} that is less than or equal to every other value in
   *     the array
   * @throws IllegalArgumentException if {@code array} is empty
   */
  @GwtIncompatible(

   * because it is seen as having the value of positive {@code 129}.
   *
   * @param a the first {@code byte} to compare
   * @param b the second {@code byte} to compare
   * @return a negative value if {@code a} is less than {@code b}; a positive value if {@code a} is
   *     greater than {@code b}; or zero if they are equal
   */
  public static int compare(byte a, byte b) {
    return toInt(a) - toInt(b);
  }

  /**

   * Contention and/or table collisions are indicated by failed
   * CASes when performing an update operation (see method
   * retryUpdate). Upon a collision, if the table size is less than
   * the capacity, it is doubled in size unless some other thread
   * holds the lock. If a hashed slot is empty, and lock is
   * available, a new Cell is created. Otherwise, if the slot