*     Guava 27.0
 */
public final class InternalFutures {
  /**
   * Usually returns {@code null} but, if the given {@code Future} has failed, may <i>optionally</i>
   * return the cause of the failure. "Failure" means specifically "completed with an exception"; it
   * does not include "was cancelled." To be explicit: If this method returns a non-null value,
   * then:
   *
   * <ul>
   *   <li>{@code isDone()} must return {@code true}

   * #transform}.
   *
   * @param exceptionType the exception type that triggers use of {@code fallback}. The exception
   *     type is matched against the input's exception. "The input's exception" means the cause of
   *     the {@link ExecutionException} thrown by {@code input.get()} or, if {@code get()} throws a
   *     different kind of exception, that exception itself. To avoid hiding bugs and other

   *
   * @since 11.0
   */
  /*
   * <? extends Object> is mostly the same as <?> to plain Java. But to nullness checkers, they
   * differ: <? extends Object> means "non-null types," while <?> means "all types."
   */
  ImmutableMap<K, V> getAllPresent(Iterable<? extends Object> keys);

  /**
   * Associates {@code value} with {@code key} in this cache. If the cache previously contained a

   * However, an implementation may also choose to return {@code true} whenever {@code object} is a
   * {@link Predicate} that it considers <i>interchangeable</i> with this one. "Interchangeable"
   * <i>typically</i> means that {@code this.apply(t) == that.apply(t)} for all {@code t} of type
   * {@code T}). Note that a {@code false} result from this method does not imply that the
   * predicates are known <i>not</i> to be interchangeable.
   */

   * doesn't work: Because nullness analyses typically infer the nullness of local variables,
   * there's no way to assign a {@code @Nullable T} to a field {@code T foo;} and instruct the
   * analysis that that means "plain {@code T}" rather than the inferred type {@code @Nullable T}.
   * (Even if supported added {@code @NonNull}, that would not help, since the problem case

   * interface, whose return type {@code AnnotatedType[]} is also new in Java 8. That means that we
   * cannot implement that interface in source code in a way that will compile on both Java 7 and
   * Java 8. If we include the {@code getAnnotatedBounds()} method then its return type means it
   * won't compile on Java 7, while if we don't include the method then the compiler will complain

 */
public class LoadingCacheSingleThreadBenchmark {
  @Param({"1000", "2000"})
  int maximumSize;

  @Param("5000")
  int distinctKeys;

  @Param("4")
  int segments;

  // 1 means uniform likelihood of keys; higher means some keys are more popular
  // tweak this to control hit rate
  @Param("2.5")
  double concentration;

  Random random = new Random();

  LoadingCache<Integer, Integer> cache;

  int max;

   * Generation, described in Knuth's "The Art of Computer Programming", Volume 4, Chapter 7,
   * Section 7.2.1.2. The iteration order follows the lexicographical order. This means that the
   * first permutation will be in ascending order, and the last will be in descending order.
   *
   * <p>Duplicate elements are considered equal. For example, the list [1, 1] will have only one

    assertEquals(Arrays.toString(events), stopwatch.readEventsAndClear());
  }

  /**
   * The stopwatch gathers events and presents them as strings. R0.6 means a delay of 0.6 seconds
   * caused by the (R)ateLimiter U1.0 means the (U)ser caused the stopwatch to sleep for a second.
   */
  static class FakeStopwatch extends SleepingStopwatch {
    long instant = 0L;

     *
     * <p>If the Thread in use is interrupted before or during execution of the tasks in {@link
     * #queue}, the Executor will complete its tasks, and then restore the interruption. This means
     * that once the Thread returns to the Executor that this Executor composes, the interruption
     * will still be present. If the composed Executor is an ExecutorService, it can respond to