/**
 * A multiset which maintains the ordering of its elements, according to either their natural order
 * or an explicit {@link Comparator}. In all cases, this implementation uses {@link
 * Comparable#compareTo} or {@link Comparator#compare} instead of {@link Object#equals} to determine
 * equivalence of instances.
 *
 * <p><b>Warning:</b> The comparison must be <i>consistent with equals</i> as explained by the

    assertThat(Booleans.trueFirst().compare(true, true)).isEqualTo(0);
    assertThat(Booleans.trueFirst().compare(false, false)).isEqualTo(0);
    assertThat(Booleans.trueFirst().compare(true, false)).isLessThan(0);
    assertThat(Booleans.trueFirst().compare(false, true)).isGreaterThan(0);
  }

  public void testFalseFirst() {
    assertThat(Booleans.falseFirst().compare(true, true)).isEqualTo(0);

    assertThat(Booleans.trueFirst().compare(true, true)).isEqualTo(0);
    assertThat(Booleans.trueFirst().compare(false, false)).isEqualTo(0);
    assertThat(Booleans.trueFirst().compare(true, false)).isLessThan(0);
    assertThat(Booleans.trueFirst().compare(false, true)).isGreaterThan(0);
  }

  public void testFalseFirst() {
    assertThat(Booleans.falseFirst().compare(true, true)).isEqualTo(0);

@ElementTypesAreNonnullByDefault
public class TreeMultimapExplicitTest extends TestCase {

  /**
   * Compare strings lengths, and if the lengths are equal compare the strings. A {@code null} is
   * less than any non-null value.
   */
  private enum StringLength implements Comparator<@Nullable String> {
    COMPARATOR;

    @Override
    public int compare(@Nullable String first, @Nullable String second) {
      if (first == second) {
        return 0;

  @SuppressWarnings("unchecked")
  private static final Comparator<Object> NATURAL_ORDER =
      new Comparator<Object>() {
        @Override
        public int compare(Object o1, Object o2) {
          return ((Comparable<Object>) o1).compareTo(o2);
        }
      };

  private final NavigableSet<E> delegate;

  public SafeTreeSet() {
    this(new TreeSet<E>());
  }

  @SuppressWarnings("unchecked")
  private static final Comparator<Object> NATURAL_ORDER =
      new Comparator<Object>() {
        @Override
        public int compare(Object o1, Object o2) {
          return ((Comparable<Object>) o1).compareTo(o2);
        }
      };

  private final NavigableMap<K, V> delegate;

  public SafeTreeMap() {
    this(new TreeMap<K, V>());
  }

  @SuppressWarnings("unchecked")
  private static final Comparator<Object> NATURAL_ORDER =
      new Comparator<Object>() {
        @Override
        public int compare(Object o1, Object o2) {
          return ((Comparable<Object>) o1).compareTo(o2);
        }
      };

  private final NavigableMap<K, V> delegate;

  public SafeTreeMap() {
    this(new TreeMap<K, V>());
  }

  ExplicitOrdering(List<T> valuesInOrder) {
    this(Maps.indexMap(valuesInOrder));
  }

  ExplicitOrdering(ImmutableMap<T, Integer> rankMap) {
    this.rankMap = rankMap;
  }

  @Override
  public int compare(T left, T right) {
    return rank(left) - rank(right); // safe because both are nonnegative
  }

  private int rank(T value) {
    Integer rank = rankMap.get(value);
    if (rank == null) {

    if (index >= 0) {
      return inclusive ? index : index + 1;
    } else {
      return ~index;
    }
  }

  // Pretend the comparator can compare anything. If it turns out it can't
  // compare two elements, it'll throw a CCE. Only methods that are specified to
  // throw CCE should call this.
  @SuppressWarnings("unchecked")
  Comparator<Object> unsafeComparator() {

    // Pretend the comparator can compare anything. If it turns out it can't
    // compare a and b, we should get a CCE or NPE on the subsequent line. Only methods
    // that are spec'd to throw CCE and NPE should call this.
    @SuppressWarnings({"unchecked", "nullness"})
    Comparator<@Nullable Object> unsafeComparator = (Comparator<@Nullable Object>) comparator;
    return unsafeComparator.compare(a, b);
  }