* also be called their <i>union</i>. If they are not, note that the span might contain values
   * that are not contained in either input range.
   *
   * <p>Like {@link #intersection(Range) intersection}, this operation is commutative, associative
   * and idempotent. Unlike it, it is always well-defined for any two input ranges.
   */
  public Range<C> span(Range<C> other) {

    List<Range<C>> asRanges = ImmutableList.copyOf(rangeSet.asRanges());

    // test that connected ranges are coalesced
    for (int i = 0; i + 1 < asRanges.size(); i++) {
      Range<C> range1 = asRanges.get(i);
      Range<C> range2 = asRanges.get(i + 1);
      assertFalse(range1.isConnected(range2));
    }

    // test that there are no empty ranges
    for (Range<C> range : asRanges) {

   * that conversion is safe.
   *
   * <p>This method is intended to help with usages of type parameters that have {@linkplain
   * ParametricNullness parametric nullness}. If a type parameter instead ranges over only non-null
   * types (or if the type is a non-variable type, like {@code String}), then code should almost
   * never use this method, preferring instead to call {@code requireNonNull} so as to benefit from

  @GwtIncompatible // java.math.BigInteger
  public void testMean() {
    // Odd-sized ranges have an obvious mean
    assertMean(2, 1, 3);

    assertMean(-2, -3, -1);
    assertMean(0, -1, 1);
    assertMean(1, -1, 3);
    assertMean((1L << 62) - 1, -1, Long.MAX_VALUE);

    // Even-sized ranges should prefer the lower mean
    assertMean(2, 1, 4);
    assertMean(-3, -4, -1);
    assertMean(0, -1, 2);

  /** The HTTP {@code User-Agent} header field name. */
  public static final String USER_AGENT = "User-Agent";

  // HTTP Response header fields

  /** The HTTP {@code Accept-Ranges} header field name. */
  public static final String ACCEPT_RANGES = "Accept-Ranges";
  /** The HTTP {@code Access-Control-Allow-Headers} header field name. */
  public static final String ACCESS_CONTROL_ALLOW_HEADERS = "Access-Control-Allow-Headers";

   * works better than Ordering.natural().nullsFirst() because, if null comes before all other
   * values, it lies outside the submap/submultiset ranges we test, and the variety of tests that
   * exercise null handling fail on those subcollections.
   */
  public abstract static class NullsBefore implements Comparator<@Nullable String>, Serializable {
    /*

import javax.annotation.CheckForNull;

/**
 * Represents an <a href="http://en.wikipedia.org/wiki/Internet_media_type">Internet Media Type</a>
 * (also known as a MIME Type or Content Type). This class also supports the concept of media ranges
 * <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1">defined by HTTP/1.1</a>.
 * As such, the {@code *} character is treated as a wildcard and is used to represent any acceptable

      for (Range<Integer> range2 : RANGES) {
        for (Range<Integer> range3 : RANGES) {
          Map<Integer, Integer> model = Maps.newHashMap();
          putModel(model, range1, 1);
          putModel(model, range2, 2);
          putModel(model, range3, 3);
          RangeMap<Integer, Integer> test = TreeRangeMap.create();
          RangeMap<Integer, Integer> test2 = TreeRangeMap.create();

      for (Range<Integer> range2 : QUERY_RANGES) {
        TreeRangeSet<Integer> rangeSet = TreeRangeSet.create();
        rangeSet.add(range1);
        rangeSet.add(range2);
        testViewAgainstExpected(expectedComplement(rangeSet), rangeSet.complement());
      }
    }
  }


  public void testSubRangeSetOfComplement() {
    for (Range<Integer> range1 : QUERY_RANGES) {

    }
  }

  @Override
  public Range<K> span() {
    if (ranges.isEmpty()) {
      throw new NoSuchElementException();
    }
    Range<K> firstRange = ranges.get(0);
    Range<K> lastRange = ranges.get(ranges.size() - 1);
    return Range.create(firstRange.lowerBound, lastRange.upperBound);
  }

  /**
   * Guaranteed to throw an exception and leave the {@code RangeMap} unmodified.