Iterator<List<Integer>> partitions = Iterators.partition(source, 1);
    assertTrue(partitions.hasNext());
    assertTrue(partitions.hasNext());
    assertEquals(ImmutableList.of(1), partitions.next());
    assertFalse(partitions.hasNext());
  }

  public void testPartition_singleton2() {
    Iterator<Integer> source = singletonIterator(1);
    Iterator<List<Integer>> partitions = Iterators.partition(source, 2);

    Iterator<List<Integer>> partitions = Iterators.partition(source, 1);
    assertTrue(partitions.hasNext());
    assertTrue(partitions.hasNext());
    assertEquals(ImmutableList.of(1), partitions.next());
    assertFalse(partitions.hasNext());
  }

  public void testPartition_singleton2() {
    Iterator<Integer> source = singletonIterator(1);
    Iterator<List<Integer>> partitions = Iterators.partition(source, 2);

   * OutOfMemoryError}.
   *
   * @param iterator the iterator to return a partitioned view of
   * @param size the desired size of each partition (the last may be smaller)
   * @return an iterator of immutable lists containing the elements of {@code iterator} divided into
   *     partitions
   * @throws IllegalArgumentException if {@code size} is nonpositive
   */

  }

  /**
   * Guides the allowed concurrency among update operations. Used as a hint for internal sizing. The
   * table is internally partitioned to try to permit the indicated number of concurrent updates
   * without contention. Because assignment of entries to these partitions is not necessarily
   * uniform, the actual concurrency observed may vary. Ideally, you should choose a value to