* Queue#isEmpty} and {@link Queue#remove()}, since {@link Queue}'s iteration order is undefined.
   * Calling {@link Iterator#hasNext()} on a generated iterator from the returned iterable may cause
   * an item to be immediately dequeued for return on a subsequent call to {@link Iterator#next()}.
   *
   * <p>Whether the input {@code iterable} is a {@link Queue} or not, the returned {@code Iterable}
   * is not thread-safe.
   *

      throw new UnsupportedOperationException();
    }
  }

  /**
   * Creates an index {@code ImmutableListMultimap} that contains the results of applying a
   * specified function to each item in an {@code Iterable} of values. Each value will be stored as
   * a value in the resulting multimap, yielding a multimap with the same size as the input

    //    to synchronize with us
    // 2. reverse the linked list, because despite our rather clear contract, people depend on us
    //    executing listeners in the order they were added
    // 3. push all the items onto 'onto' and return the new head of the stack
    Listener head = ATOMIC_HELPER.gasListeners(this, Listener.TOMBSTONE);
    Listener reversedList = onto;
    while (head != null) {
      Listener tmp = head;

    Enumeration<Integer> enumer = enumerate(1, 2, 3);
    Iterator<Integer> iter = Iterators.forEnumeration(enumer);

    assertTrue(iter.hasNext());
    assertEquals(1, (int) iter.next());
    assertTrue(iter.hasNext());
    assertEquals(2, (int) iter.next());
    assertTrue(iter.hasNext());
    assertEquals(3, (int) iter.next());
    assertFalse(iter.hasNext());
  }

  public void testAsEnumerationEmpty() {