return new Builder<>(Ordering.natural());
  }

  /**
   * Returns a builder that creates immutable sorted maps with an explicit comparator. If the
   * comparator has a more general type than the map's keys, such as creating a {@code
   * SortedMap<Integer, String>} with a {@code Comparator<Number>}, use the {@link Builder}
   * constructor instead.
   *

    return new Builder<>(Ordering.natural());
  }

  /**
   * Returns a builder that creates immutable sorted maps with an explicit comparator. If the
   * comparator has a more general type than the map's keys, such as creating a {@code
   * SortedMap<Integer, String>} with a {@code Comparator<Number>}, use the {@link Builder}
   * constructor instead.
   *