assertSame(Ordering.natural(), copyFromSorted.keyComparator());
    assertSame(Ordering.natural(), copyFromSorted.valueComparator());
    assertSame(Ordering.natural(), copyFromSorted.get(1.0).comparator());
  }

  public void testComparators() {
    TreeMultimap<String, Integer> multimap = TreeMultimap.create();
    assertEquals(Ordering.natural(), multimap.keyComparator());

    final @Nullable Comparator<? super K> keyComparator;

    public EntryComparator(@Nullable Comparator<? super K> keyComparator) {
      this.keyComparator = keyComparator;
    }

    @Override
    @SuppressWarnings("unchecked") // no less safe than putting it in the map!
    public int compare(Entry<K, V> a, Entry<K, V> b) {
      return (keyComparator == null)

    final @Nullable Comparator<? super K> keyComparator;

    public EntryComparator(@Nullable Comparator<? super K> keyComparator) {
      this.keyComparator = keyComparator;
    }

    @Override
    @SuppressWarnings("unchecked") // no less safe than putting it in the map!
    public int compare(Entry<K, V> a, Entry<K, V> b) {
      return (keyComparator == null)

     * Specifies the ordering of the generated multimap's keys.
     *
     * @since 8.0
     */
    @CanIgnoreReturnValue
    public Builder<K, V> orderKeysBy(Comparator<? super K> keyComparator) {
      this.keyComparator = checkNotNull(keyComparator);
      return this;
    }

    /**
     * Specifies the ordering of the generated multimap's values for each key.
     *
     * @since 8.0
     */