* <p>If you are escaping input in arbitrary successive chunks, then it is not generally safe to
   * use this method. If an input string ends with an unmatched high surrogate character, then this
   * method will throw {@link IllegalArgumentException}. You should ensure your input is valid <a
   * href="http://en.wikipedia.org/wiki/UTF-16">UTF-16</a> before calling this method.
   *

 * then reverse that result.
 *
 * <h3>Additional notes</h3>
 *
 * <p>Except as noted, the orderings returned by the factory methods of this class are serializable
 * if and only if the provided instances that back them are. For example, if {@code ordering} and
 * {@code function} can themselves be serialized, then {@code ordering.onResultOf(function)} can as
 * well.
 *

 * the {@link #startUp} and {@link #shutDown} methods and also uses that service to schedule the
 * {@link #runOneIteration} that will be executed periodically as specified by its {@link
 * Scheduler}. When this service is asked to stop via {@link #stopAsync} it will cancel the periodic
 * task (but not interrupt it) and wait for it to stop before running the {@link #shutDown} method.
 *

 * </ul>
 *
 * <p>Consumers of this annotation include:
 *
 * <ul>
 *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
 *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
 *       to "undo" {@link ElementTypesAreNonnullByDefault}. It is the best we can do for Kotlin
 *       under our current constraints.

 * </ul>
 *
 * <p>Consumers of this annotation include:
 *
 * <ul>
 *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
 *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
 *       to "undo" {@link ElementTypesAreNonnullByDefault}. It is the best we can do for Kotlin
 *       under our current constraints.

   * {@code short[]}, or {@code int[]}. The value of {@code entry} should fit in the size of the
   * assigned array element, when seen as an unsigned value. So if {@code table} is a {@code byte[]}
   * then we should have {@code 0 ≤ entry ≤ 255}, and if {@code table} is a {@code short[]} then we
   * should have {@code 0 ≤ entry ≤ 65535}. It is the caller's responsibility to ensure this.
   */

   * {@code short[]}, or {@code int[]}. The value of {@code entry} should fit in the size of the
   * assigned array element, when seen as an unsigned value. So if {@code table} is a {@code byte[]}
   * then we should have {@code 0 ≤ entry ≤ 255}, and if {@code table} is a {@code short[]} then we
   * should have {@code 0 ≤ entry ≤ 65535}. It is the caller's responsibility to ensure this.
   */

   *
   * // Falling back to a zero counter in case an exception happens when
   * // processing the RPC to fetch counters.
   * ListenableFuture<Integer> faultTolerantFuture = Futures.catching(
   *     fetchCounterFuture, FetchException.class, x -> 0, directExecutor());
   * }</pre>
   *
   * <p>When selecting an executor, note that {@code directExecutor} is dangerous in some cases. See

   * consideration by {@link #maximumWeight(long)} when determining which entries to evict, and use
   * of this method requires a corresponding call to {@link #maximumWeight(long)} prior to calling
   * {@link #build}. Weights are measured and recorded when entries are inserted into the cache, and
   * are thus effectively static during the lifetime of a cache entry.
   *

  }

  /**
   * Inserts element at current put position, advances, and signals. Call only when occupying
   * monitor.
   */
  private void insert(E x) {
    items[putIndex] = x;
    putIndex = inc(putIndex);
    ++count;
  }

  /**
   * Extracts element at current take position, advances, and signals. Call only when occupying
   * monitor.
   */
  private E extract() {
    final E[] items = this.items;