}

  public void testCustomComparator() throws Exception {
    Comparator<String> comparator =
        new Comparator<String>() {
          @Override
          public int compare(String o1, String o2) {
            return o2.compareTo(o1);
          }
        };
    TreeMultiset<String> ms = TreeMultiset.create(comparator);

    ms.add("b");
    ms.add("c");
    ms.add("a");
    ms.add("b");

  }

  private static class IntegerDiv10 implements Comparable<IntegerDiv10> {
    final int value;

    IntegerDiv10(int value) {
      this.value = value;
    }

    @Override
    public int compareTo(IntegerDiv10 o) {
      return value / 10 - o.value / 10;
    }

    @Override
    public String toString() {
      return Integer.toString(value);
    }
  }

            // Remove oldest sessions
            sessionCache.entrySet()
                    .stream()
                    .sorted((e1, e2) -> e1.getValue().getLastAccessedAt().compareTo(e2.getValue().getLastAccessedAt()))
                    .limit(toRemove)
                    .map(Map.Entry::getKey)
                    .collect(Collectors.toList())
                    .forEach(sessionCache::remove);

   * to the JDK until JDK 7.
   *
   * @param a the first {@code double} to compare
   * @param b the second {@code double} to compare
   * @return a negative value if {@code a} is less than {@code b}; a positive value if {@code a} is
   *     greater than {@code b}; or zero if they are equal
   */
  @InlineMe(replacement = "Double.compare(a, b)")
  public static int compare(double a, double b) {

                      @Override
                      public int compare(Entry<String, String> left, Entry<String, String> right) {
                        return ComparisonChain.start()
                            .compare(left.getKey(), right.getKey(), Ordering.natural().nullsFirst())
                            .compare(
                                left.getValue(), right.getValue(), Ordering.natural().nullsFirst())

                    return -1;
                }
                if (timeObj2 == null) {
                    return 1;
                }

                return o1.toString().compareTo(o2.toString());
            });
            return array;
        } catch (final IndexNotFoundException e) {
            return new Map[0];
        }
    }

    /**
     * Add a value to array index.

    return new NullFriendlyComparator<>();
  }

  private static final class NullFriendlyComparator<T> implements Comparator<T>, Serializable {
    @Override
    public int compare(T left, T right) {
      return String.valueOf(left).compareTo(String.valueOf(right));
    }
  }

   * @param b the second {@code boolean} to compare
   * @return a positive number if only {@code a} is {@code true}, a negative number if only {@code
   *     b} is true, or zero if {@code a == b}
   */
  @InlineMe(replacement = "Boolean.compare(a, b)")
  public static int compare(boolean a, boolean b) {
    return Boolean.compare(a, b);
  }

  /**

  }

  private static class IntegerDiv10 implements Comparable<IntegerDiv10> {
    final int value;

    IntegerDiv10(int value) {
      this.value = value;
    }

    @Override
    public int compareTo(IntegerDiv10 o) {
      return value / 10 - o.value / 10;
    }

    @Override
    public String toString() {
      return Integer.toString(value);
    }
  }

  }

  public void testExplicit_two() {
    Comparator<Integer> c = Ordering.explicit(42, 5);
    assertEquals(0, c.compare(5, 5));
    assertTrue(c.compare(5, 42) > 0);
    assertTrue(c.compare(42, 5) < 0);
    IncomparableValueException expected =
        assertThrows(IncomparableValueException.class, () -> c.compare(5, 666));
    assertEquals(666, expected.value);
    new EqualsTester()