.put(IllegalArgumentException.class, e -> e instanceof IllegalArgumentException)
          .put(IllegalStateException.class, e -> e instanceof IllegalStateException)
          .put(IncomparableValueException.class, e -> e instanceof IncomparableValueException)
          .put(IndexOutOfBoundsException.class, e -> e instanceof IndexOutOfBoundsException)
          .put(NoSuchElementException.class, e -> e instanceof NoSuchElementException)

    return rank(left) - rank(right); // safe because both are nonnegative
  }

  private int rank(T value) {
    Integer rank = rankMap.get(value);
    if (rank == null) {
      throw new IncomparableValueException(value);
    }
    return rank;
  }

  @Override
  public boolean equals(@Nullable Object object) {
    if (object instanceof ExplicitOrdering) {