return emptySet(comparator());
    }
  }

  @CheckForNull
  E higher(E e) {
    checkNotNull(e);
    Iterator<E> iterator = tailSet(e).iterator();
    while (iterator.hasNext()) {
      E higher = iterator.next();
      if (comparator().compare(e, higher) < 0) {
        return higher;
      }
    }
    return null;
  }

  @CheckForNull
  public E ceiling(E e) {

		ipList       []string
		sortedIPList []string
	}{
		// Default case of two ips one with higher octet moves
		// to the beginning of the list.
		{
			ipList:       []string{"127.0.0.1", "10.0.0.13"},
			sortedIPList: []string{"10.0.0.13", "127.0.0.1"},
		},
		// With multiple types of octet, chooses a higher octet.
		{
			ipList:       []string{"127.0.0.1", "172.0.21.1", "192.168.1.106"},

    /**
     * Gets the problems that were encountered during the settings building. Note that only problems of severity
     * {@link BuilderProblem.Severity#WARNING} and below are reported here. Problems with a higher severity level cause
     * the settings builder to fail with a {@link SettingsBuilderException}.
     *
     * @return the problems that were encountered during the settings building, can be empty but never {@code null}
     */

    /**
     * Gets the problems that were encountered during the settings building. Note that only problems of severity
     * {@link BuilderProblem.Severity#WARNING} and below are reported here. Problems with a higher severity level cause
     * the settings builder to fail with a {@link ToolchainsBuilderException}.
     *
     * @return the problems that were encountered during the settings building, can be empty but never {@code null}

  @CheckForNull
  public K firstKey() {
    return sortedDelegate.firstKey();
  }

  @CheckForNull
  public K lastKey() {
    return sortedDelegate.lastKey();
  }

  @CheckForNull
  K higher(K k) {
    Iterator<K> iterator = keySet().tailSet(k).iterator();
    while (iterator.hasNext()) {
      K tmp = iterator.next();
      if (comparator().compare(k, tmp) < 0) {
        return tmp;
      }
    }

	}

	ipList = set.NewStringSet()
	for _, addr := range addrs {
		ipList.Add(addr)
	}

	return ipList, err
}

// sortIPs - sort ips based on higher octets.
// The logic to sort by last octet is implemented to
// prefer CIDRs with higher octets, this in-turn skips the
// localhost/loopback address to be not preferred as the
// first ip on the list. Subsequently this list helps us print

              KeyAbsentBehavior.NEXT_HIGHER);
    } else {
      fromIndex = 0;
    }

    int toIndex;
    if (range.hasUpperBound()) {
      toIndex =
          SortedLists.binarySearch(
              ranges,
              Range::lowerBound,
              range.upperBound,
              KeyPresentBehavior.FIRST_PRESENT,
              KeyAbsentBehavior.NEXT_HIGHER);
    } else {

              KeyAbsentBehavior.NEXT_HIGHER);
    } else {
      fromIndex = 0;
    }

    int toIndex;
    if (range.hasUpperBound()) {
      toIndex =
          SortedLists.binarySearch(
              ranges,
              Range::lowerBound,
              range.upperBound,
              KeyPresentBehavior.FIRST_PRESENT,
              KeyAbsentBehavior.NEXT_HIGHER);
    } else {

            KeyPresentBehavior.FIRST_AFTER,
            KeyAbsentBehavior.NEXT_HIGHER);
    int upperIndex =
        SortedLists.binarySearch(
            ranges,
            Range::lowerBound,
            range.upperBound,
            KeyPresentBehavior.ANY_PRESENT,
            KeyAbsentBehavior.NEXT_HIGHER);
    if (lowerIndex >= upperIndex) {
      return ImmutableRangeMap.of();
    }

     * <li><code>[1.0,2.0]</code> Versions 1.0 to 2.0 (both included)</li>
     * <li><code>[1.5,)</code> Versions 1.5 and higher</li>
     * <li><code>(,1.0],[1.2,)</code> Versions up to 1.0 (included) and 1.2 or higher</li>
     * </ul>
     *
     * @param spec string representation of a version or version range
     * @return a new {@link VersionRange} object that represents the spec