Iterator<Integer> source = Iterators.singletonIterator(1);
    try {
      Iterators.partition(source, 0);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testPartition_empty() {
    Iterator<Integer> source = Iterators.emptyIterator();
    Iterator<List<Integer>> partitions = Iterators.partition(source, 1);
    assertFalse(partitions.hasNext());
  }

    private void writeObject(ObjectOutputStream stream) throws IOException {
      synchronized (mutex) {
        stream.defaultWriteObject();
      }
    }

    @GwtIncompatible // not needed in emulated source
    @J2ktIncompatible
    private static final long serialVersionUID = 0;
  }

  private static <E extends @Nullable Object> Collection<E> collection(
      Collection<E> collection, @CheckForNull Object mutex) {

    Iterator<Integer> source = singletonIterator(1);
    try {
      Iterators.partition(source, 0);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testPartition_empty() {
    Iterator<Integer> source = Iterators.emptyIterator();
    Iterator<List<Integer>> partitions = Iterators.partition(source, 1);
    assertFalse(partitions.hasNext());
  }

      setMap(map);
    }

    @GwtIncompatible // not needed in emulated source
    @J2ktIncompatible
    private static final long serialVersionUID = 0;
  }

  /**
   * Copies each key-value mapping in {@code source} into {@code dest}, with its key and value
   * reversed.
   *
   * <p>If {@code source} is an {@link ImmutableMultimap}, consider using {@link
   * ImmutableMultimap#inverse} instead.

  }

  /**
   * Specifies a nanosecond-precision time source for this cache. By default, {@link
   * System#nanoTime} is used.
   *
   * <p>The primary intent of this method is to facilitate testing of caches with a fake or mock
   * time source.
   *
   * @return this {@code CacheBuilder} instance (for chaining)

      }
    };
  }

  /**
   * Combines two iterators into a single iterator. The returned iterator iterates across the
   * elements in {@code a}, followed by the elements in {@code b}. The source iterators are not
   * polled until necessary.
   *
   * <p>The returned iterator supports {@code remove()} when the corresponding input iterator
   * supports it.
   */

      }
    };
  }

  /**
   * Combines two iterators into a single iterator. The returned iterator iterates across the
   * elements in {@code a}, followed by the elements in {@code b}. The source iterators are not
   * polled until necessary.
   *
   * <p>The returned iterator supports {@code remove()} when the corresponding input iterator
   * supports it.
   */