int j = findNextJ();
      if (j == -1) {
        nextPermutation = null;
        return;
      }
      /*
       * requireNonNull is safe because we don't clear nextPermutation until we're done calling this
       * method.
       */
      requireNonNull(nextPermutation);

      int l = findNextL(j);
      Collections.swap(nextPermutation, j, l);
      int n = nextPermutation.size();

    listenableFuture.addListener(singleCallListener, directExecutor());
    assertEquals(DATA1, listenableFuture.get());

    // 'spy' should have been ignored since 'abstractFuture' was done before
    // a listener was added.
    assertFalse(spy.wasExecuted);
    assertTrue(singleCallListener.wasCalled());
    assertTrue(listenableFuture.isDone());
  }

    @Override
    public Map<String, Collection<Integer>> create(Object... elements) {
      ImmutableMap.Builder<String, Integer> builder = ImmutableMap.builder();
      // assumes that each set is a singleton or less (as is done for the samples)
      for (Object elem : elements) {
        @SuppressWarnings("unchecked") // safe by generator contract
        Entry<String, Collection<Integer>> entry = (Entry<String, Collection<Integer>>) elem;

 * Executor, and sequentially such that no two will ever be running at the same time.
 *
 * <p>Tasks submitted to {@link #execute(Runnable)} are executed in FIFO order.
 *
 * <p>The execution of tasks is done by one thread as long as there are tasks left in the queue.
 * When a task is {@linkplain Thread#interrupt interrupted}, execution of subsequent tasks
 * continues. See {@link QueueWorker#workOnQueue} for details.
 *

repeated in a wondering tone.

  `Why, what are YOUR shoes done with?' said the Gryphon.  `I
mean, what makes them so shiny?'

  Alice looked down at them, and considered a little before she
gave her answer.  `They're done with blacking, I believe.'

  `Boots and shoes under the sea,' the Gryphon went on in a deep
voice, `are done with a whiting.  Now you know.'

 * Implementation detail for the internal structure of {@link Range} instances. Represents a unique
 * way of "cutting" a "number line" (actually of instances of type {@code C}, not necessarily
 * "numbers") into two sections; this can be done below a certain value, above a certain value,
 * below all values or above all values. With this object defined in this way, an interval can
 * always be represented by a pair of {@code Cut} instances.
 *

 *
 * <p>In order to allow proper garbage collection of unused locks, the edges of the lock graph are
 * weak references.
 *
 * <p><strong>Performance</strong>
 *
 * <p>The extra bookkeeping done by cycle detecting locks comes at some cost to performance.
 * Benchmarks (as of December 2011) show that:
 *
 * <ul>
 *   <li>for an unnested {@code lock()} and {@code unlock()}, a cycle detecting lock takes 38ns as

    } else if (type instanceof WildcardType) {
      return resolveWildcardType((WildcardType) type);
    } else {
      // if Class<?>, no resolution needed, we are done.
      return type;
    }
  }

  Type[] resolveTypesInPlace(Type[] types) {
    for (int i = 0; i < types.length; i++) {
      types[i] = resolveType(types[i]);
    }
    return types;
  }

     * index. This constructor is optimized so that it starts at either the head or the tail,
     * depending on which is closer to the specified index. This allows adds to the tail to be done
     * in constant time.
     *
     * @throws IndexOutOfBoundsException if index is invalid
     */
    public ValueForKeyIterator(@ParametricNullness K key, int index) {

       * that behavior is undefined when the backing map is modified through another API. (It even
       * permits us to throw IllegalStateException. Maybe we should have done that, but we probably
       * shouldn't change now for fear of breaking people.)
       *
       * If the entry is still in the map, then updateIndex ensured that `index` points to the right