if (!expression) {
      throw new IllegalStateException(lenientFormat(errorMessageTemplate, p1, p2, p3, p4));
    }
  }

  /*
   * Preconditions.checkNotNull is *intended* for performing eager null checks on parameters that a
   * nullness checker can already "prove" are non-null. That means that the first parameter to
   * checkNotNull *should* be annotated to require it to be non-null.
   *

    for (Class<?> eventType : eventTypes) {
      CopyOnWriteArraySet<Subscriber> eventSubscribers = subscribers.get(eventType);
      if (eventSubscribers != null) {
        // eager no-copy snapshot
        subscriberIterators.add(eventSubscribers.iterator());
      }
    }

    return Iterators.concat(subscriberIterators.iterator());
  }

  /**

      return list.asList();
    }
    return copyFromCollection(elements);
  }

  @JsMethod
  public static <E> ImmutableList<E> copyOf(E[] elements) {
    checkNotNull(elements); // eager for GWT
    return copyOf(Arrays.asList(elements));
  }

  private static <E> ImmutableList<E> copyFromCollection(Collection<? extends E> collection) {
    Object[] elements = collection.toArray();

passage, not much larger than a rat-hole:  she knelt down and
looked along the passage into the loveliest garden you ever saw.
How she longed to get out of that dark hall, and wander about
among those beds of bright flowers and those cool fountains, but
she could not even get her head though the doorway; `and even if
my head would go through,' thought poor Alice, `it would be of

 * ImmutableMultiset_CustomFieldSerializer. But that type has no methods (since it's never actually
 * used). We could probably fix the problem by adding dummy methods to that class, but that is
 * starting to sound harder than taking the superclass approach, which I've been coming to like,
 * anyway, since it doesn't require us to declare dummy methods (though occasionally constructors)
 * and make types non-final.
 */

  static final int SAMPLE_MASK = 0xFF;

  /**
   * Compute arrays of valid unicode text, and store it in 3 forms: byte arrays, Strings, and
   * StringBuilders (in a CharSequence[] to make it a little harder for the JVM).
   */
  @BeforeExperiment
  void setUp() {
    final long seed = 99;
    final Random rnd = new Random(seed);
    strings = new String[SAMPLES];
    for (int i = 0; i < SAMPLES; i++) {