return current;
  }

  /**
   * Returns the unique least value of type {@code C} that is greater than {@code value}, or {@code
   * null} if none exists. Inverse operation to {@link #previous}.
   *
   * @param value any value of type {@code C}
   * @return the least value greater than {@code value}, or {@code null} if {@code value} is {@code
   *     maxValue()}
   */
  @CheckForNull
  public abstract C next(C value);

   * rate limiter will release one permit every {@code (1.0 / permitsPerSecond)} seconds. When the
   * rate limiter is unused, bursts of up to {@code permitsPerSecond} permits will be allowed, with
   * subsequent requests being smoothly limited at the stable rate of {@code permitsPerSecond}.
   *
   * @param permitsPerSecond the rate of the returned {@code RateLimiter}, measured in how many

   * Multimap} entries in two distinct modes:
   *
   * <ul>
   *   <li>To output a separate entry for each key-value pair, pass {@code multimap.entries()} to a
   *       {@code MapJoiner} method that accepts entries as input, and receive output of the form
   *       {@code key1=A&key1=B&key2=C}.
   *   <li>To output a single entry for each key, pass {@code multimap.asMap()} to a {@code

   * the members of the element set of {@code multiset2} that are not contained in {@code
   * multiset1}, with repeated occurrences of the same element appearing consecutively.
   *
   * <p>Results are undefined if {@code multiset1} and {@code multiset2} are based on different
   * equivalence relations (as {@code HashMultiset} and {@code TreeMultiset} are).
   *
   * @since 14.0

 * comparator utilities, see either {@code Comparator} itself (for Java 8+), or {@code
 * com.google.common.collect.Ordering} (otherwise).
 *
 * <h3>Relationship to {@code Ordering}</h3>
 *
 * <p>In light of the significant enhancements to {@code Comparator} in Java 8, the overwhelming
 * majority of usages of {@code Ordering} can be written using only built-in JDK APIs. This class is

 *
 * <p>As this interface extends {@code java.util.function.Predicate}, an instance of this type may
 * be used as a {@code Predicate} directly. To use a {@code java.util.function.Predicate} where a
 * {@code com.google.common.base.Predicate} is expected, use the method reference {@code
 * predicate::test}.
 *
 * <p>This interface is now a legacy type. Use {@code java.util.function.Predicate} (or the

   * String.class}, then {@code new TypeResolver().where(formal, actual)} will {@linkplain
   * #resolveType resolve} {@code ParameterizedType List<T>} to {@code List<String>}, and resolve
   * {@code Map<T, Something>} to {@code Map<String, Something>} etc. Similarly, {@code formal} and
   * {@code actual} can be {@code Map<K, V>} and {@code Map<String, Integer>} respectively, or they

 * .compare(a.foo, b.bar)}. {@code ComparisonChain} also has a potential performance problem that
 * {@code Comparator} doesn't: it evaluates all the parameters of all the {@code .compare} calls,
 * even when the result of the comparison is already known from previous {@code .compare} calls.
 * That can be expensive.
 *
 * @author Mark Davis
 * @author Kevin Bourrillion
 * @since 2.0
 */
@GwtCompatible

  /**
   * Computes or retrieves the value corresponding to {@code key}.
   *
   * @param key the non-null key whose value should be loaded
   * @return the value associated with {@code key}; <b>must not be null</b>
   * @throws Exception if unable to load the result
   * @throws InterruptedException if this method is interrupted. {@code InterruptedException} is
   *     treated like any other {@code Exception} in all respects except that, when it is caught,

   * execute/submit/schedule}, as in {@link CallerRunsPolicy}. This applies both to individually
   * submitted tasks and to collections of tasks submitted via {@code invokeAll}, {@code invokeAny},
   * {@code schedule}, {@code scheduleAtFixedRate}, and {@code scheduleWithFixedDelay}. In the case
   * of tasks submitted by {@code invokeAll} or {@code invokeAny}, tasks will run serially on the