/**
   * Verifies that an Iterator is unmodifiable.
   *
   * <p>This test only works with iterators that iterate over a finite set.
   */
  public static void assertIteratorIsUnmodifiable(Iterator<?> iterator) {
    while (iterator.hasNext()) {
      iterator.next();
      try {
        iterator.remove();
        fail("Remove on unmodifiable iterator succeeded");
      } catch (UnsupportedOperationException expected) {
      }
    }

      Iterable<? extends T> iterable, Comparator<T> comparator) {
    checkNotNull(comparator);
    Iterator<? extends T> it = iterable.iterator();
    if (it.hasNext()) {
      T prev = it.next();
      while (it.hasNext()) {
        T next = it.next();
        if (comparator.compare(prev, next) > 0) {
          return false;
        }
        prev = next;
      }
    }
    return true;
  }

  /**

   *
   * <p>Why <i>not</i> just add {@code SuppressWarnings}? The problem is that this method is
   * typically useful for {@code return} statements. That leaves the code with two options: Either
   * add the suppression to the whole method (which turns off checking for a large section of code),
   * or extract a variable, and put the suppression on that. However, a local variable typically

        add(checkNotNull(element));
      }
      return this;
    }

    @CanIgnoreReturnValue
    public Builder<E> addAll(Iterator<? extends E> elements) {
      checkNotNull(elements); // for GWT
      while (elements.hasNext()) {
        add(checkNotNull(elements.next()));
      }
      return this;
    }

    public abstract ImmutableCollection<E> build();
  }

    a.set(0, 1.0);
    Thread t =
        newStartedThread(
            new CheckedRunnable() {
              @Override
              public void realRun() {
                while (!a.compareAndSet(0, 2.0, 3.0)) {
                  Thread.yield();
                }
              }
            });

    assertTrue(a.compareAndSet(0, 1.0, 2.0));
    awaitTermination(t);

 * factory that created it. This allows detection of cycles across components while delegating
 * control over lock behavior to individual components.
 *
 * <p>Applications are encouraged to use a {@code CycleDetectingLockFactory} to create any locks for
 * which external/unmanaged code is executed while the lock is held. (See caveats under
 * <strong>Performance</strong>).
 *
 * <p><strong>Cycle Detection</strong>

    for (int i = 0; i < 11; i++) {
      limiter.acquire(); // #7, showing off the warmup starting from totally cold
    }

    // make sure the areas (times) remain the same, while permits are different
    assertEvents(
        "R0.00, R1.38, R1.13, R0.88, R0.63, R0.50, R0.50, R0.50", // #1
        "U4.50", // #2
        "R0.00, R1.38, R1.13", // #3, after that the rate changes

          // shift is either the number of powers of 2 left to multiply a by, or the biggest shift
          // possible while keeping a in an unsigned long.
          a = UnsignedLongs.remainder(a << shift, m);
          remainingPowersOf2 -= shift;
        } while (remainingPowersOf2 > 0);
        return a;
      }

      @Override
      long mulMod(long a, long b, long m) {

 * common to all multimaps.
 *
 * <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods each return a {@link
 * Set} of values, while {@link #entries} returns a {@code Set} of map entries. Though the method
 * signature doesn't say so explicitly, the map returned by {@link #asMap} has {@code Set} values.
 *

      }
      return;
    }

    // Let's play quickselect! We'll repeatedly partition the range [from, to] containing the
    // required element, as long as it has more than one element.
    while (to > from) {
      int partitionPoint = partition(array, from, to);
      if (partitionPoint >= required) {
        to = partitionPoint - 1;
      }
      if (partitionPoint <= required) {