enemies = Sets.newHashSet("Dick", "Harry", "Tom");
  }

  public void testUnion() {
    Set<String> all = Sets.union(friends, enemies);
    assertEquals(5, all.size());

    ImmutableSet<String> immut = Sets.union(friends, enemies).immutableCopy();
    HashSet<String> mut = Sets.union(friends, enemies).copyInto(new HashSet<String>());

    enemies.add("Buck");
    assertEquals(6, all.size());

    enemies = Sets.newHashSet("Dick", "Harry", "Tom");
  }

  public void testUnion() {
    Set<String> all = Sets.union(friends, enemies);
    assertEquals(5, all.size());

    ImmutableSet<String> immut = Sets.union(friends, enemies).immutableCopy();
    HashSet<String> mut = Sets.union(friends, enemies).copyInto(new HashSet<String>());

    enemies.add("Buck");
    assertEquals(6, all.size());

    assertThat(Multisets.union(ms1, ms2)).containsExactly("a", "a", "b", "b", "c");
  }

  public void testUnionEqualMultisets() {
    Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
    Multiset<String> ms2 = HashMultiset.create(Arrays.asList("a", "b", "a"));
    assertEquals(ms1, Multisets.union(ms1, ms2));
  }

  public void testUnionEmptyNonempty() {

    assertThat(Multisets.union(ms1, ms2)).containsExactly("a", "a", "b", "b", "c");
  }

  public void testUnionEqualMultisets() {
    Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
    Multiset<String> ms2 = HashMultiset.create(Arrays.asList("a", "b", "a"));
    assertEquals(ms1, Multisets.union(ms1, ms2));
  }

  public void testUnionEmptyNonempty() {

      return ((Multiset<?>) elements).elementSet().size();
    }
    return 11; // initial capacity will be rounded up to 16
  }

  /**
   * Returns an unmodifiable view of the union of two multisets. In the returned multiset, the count
   * of each element is the <i>maximum</i> of its counts in the two backing multisets. The iteration

    return result;
  }

  /**
   * Returns a new range set consisting of the union of this range set and {@code other}.
   *
   * <p>This is essentially the same as {@code TreeRangeSet.create(this).addAll(other)} except it
   * returns an {@code ImmutableRangeSet}.
   *
   * @since 21.0
   */
  public ImmutableRangeSet<C> union(RangeSet<C> other) {
    return unionOf(Iterables.concat(asRanges(), other.asRanges()));
  }

    return result;
  }

  /**
   * Returns a new range set consisting of the union of this range set and {@code other}.
   *
   * <p>This is essentially the same as {@code TreeRangeSet.create(this).addAll(other)} except it
   * returns an {@code ImmutableRangeSet}.
   *
   * @since 21.0
   */
  public ImmutableRangeSet<C> union(RangeSet<C> other) {
    return unionOf(Iterables.concat(asRanges(), other.asRanges()));
  }

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,

  //
  // Element-level accessors
  //

  /**
   * Returns a live view of the nodes which have an incident edge in common with {@code node} in
   * this graph.
   *
   * <p>This is equal to the union of {@link #predecessors(Object)} and {@link #successors(Object)}.
   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}

            .add(Range.closedOpen(5, 10))
            .add(Range.closedOpen(12, 15))
            .add(Range.openClosed(15, 17))
            .add(Range.open(19, 20))
            .build();

    assertThat(RANGE_SET_ONE.union(RANGE_SET_TWO)).isEqualTo(expected);
  }

  public void testIntersection() {
    RangeSet<Integer> expected =
        ImmutableRangeSet.<Integer>builder()
            .add(Range.closed(2, 3))