/**
   * Creates an empty {@code TreeMultimap} ordered by the natural ordering of its keys and values.
   */
  @SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
  public static <K extends Comparable, V extends Comparable> TreeMultimap<K, V> create() {
    return new TreeMultimap<>(Ordering.natural(), Ordering.natural());
  }

  /**

            .allowsSelfLoops(true)
            .nodeOrder(ElementOrder.<String>natural())
            .immutable()
            .build();

    assertThat(emptyGraph.isDirected()).isTrue();
    assertThat(emptyGraph.allowsSelfLoops()).isTrue();
    assertThat(emptyGraph.nodeOrder()).isEqualTo(ElementOrder.<String>natural());
  }

  /**

  }

  public void testFromRangeAll() {
    assertEquals(GeneralRange.all(Ordering.natural()), GeneralRange.from(Range.all()));
  }

  public void testFromRangeOneEnd() {
    for (BoundType endpointType : BoundType.values()) {
      assertEquals(
          GeneralRange.upTo(Ordering.natural(), 3, endpointType),
          GeneralRange.from(Range.upTo(3, endpointType)));

      assertEquals(

    sortedTable = TreeBasedTable.create();
    sortedTable.put("", 42, 'x');
    assertSame(Ordering.natural(), sortedTable.columnComparator());
    assertSame(
        Ordering.natural(),
        ((SortedMap<Integer, Character>) sortedTable.rowMap().values().iterator().next())
            .comparator());

    sortedTable = TreeBasedTable.create(Collections.reverseOrder(), Ordering.usingToString());

                  @Override
                  protected SortedMap<String, String> create(Entry<String, String>[] entries) {
                    NavigableMap<String, String> map = new SafeTreeMap<>(Ordering.natural());
                    for (Entry<String, String> entry : entries) {
                      map.put(entry.getKey(), entry.getValue());
                    }
                    return map;
                  }

      fail();
    } catch (IllegalArgumentException expected) {
    }
    try {
      TopKSelector.least(-1, Ordering.natural());
      fail();
    } catch (IllegalArgumentException expected) {
    }
    try {
      TopKSelector.greatest(-1, Ordering.natural());
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testZeroK() {

   * KeyAbsentBehavior)} using {@link Ordering#natural}.
   */
  @SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
  public static <E extends Comparable> int binarySearch(
      List<? extends E> list,
      E e,
      KeyPresentBehavior presentBehavior,
      KeyAbsentBehavior absentBehavior) {
    checkNotNull(e);
    return binarySearch(list, e, Ordering.natural(), presentBehavior, absentBehavior);
  }

   * relative to the natural ordering of the elements, and returns them via {@link #topK} in
   * ascending order.
   *
   * @throws IllegalArgumentException if {@code k < 0} or {@code k > Integer.MAX_VALUE / 2}
   */
  public static <T extends Comparable<? super T>> TopKSelector<T> least(int k) {
    return least(k, Ordering.natural());
  }

  /**

        builder.orderEntriesByValue(Ordering.natural()).build();
    assertMapEquals(keyOrdered, "four", 4, "one", 1);
    assertMapEquals(valueOrdered, "one", 1, "four", 4);
  }

  public void testBuilder_orderEntriesByValue_usedTwiceFails() {
    ImmutableBiMap.Builder<String, Integer> builder =
        new Builder<String, Integer>().orderEntriesByValue(Ordering.natural());
    try {

      SortedSet<E> sortedSet) {
    Comparator<? super E> result = sortedSet.comparator();
    if (result == null) {
      result = (Comparator<? super E>) Ordering.natural();
    }
    return result;
  }