// overlap
        checkInvalidRange("[1.1,1.3),(1.0,1.2]");
        // ordering
        checkInvalidRange("(1.1,1.2],[1.0,1.1)");
    }

    @Test
    void testIntersections() throws InvalidVersionSpecificationException {
        VersionRange range1 = VersionRange.createFromVersionSpec("1.0");
        VersionRange range2 = VersionRange.createFromVersionSpec("1.1");

    enemies.add("Buck");
    assertEquals(6, all.size());
    assertEquals(5, immut.size());
    assertEquals(5, mut.size());
  }

  public void testIntersection() {
    Set<String> friends = newHashSet("Tom", "Joe", "Dave");
    Set<String> enemies = newHashSet("Dick", "Harry", "Tom");

    Set<String> frenemies = Sets.intersection(friends, enemies);

    enemies.add("Buck");
    assertEquals(6, all.size());
    assertEquals(5, immut.size());
    assertEquals(5, mut.size());
  }

  public void testIntersection() {
    Set<String> friends = newHashSet("Tom", "Joe", "Dave");
    Set<String> enemies = newHashSet("Dick", "Harry", "Tom");

    Set<String> frenemies = Sets.intersection(friends, enemies);

    assertEquals(
        ImmutableSet.of(),
        ContiguousSet.create(Range.closed(-5, -1), integers())
            .intersection(ContiguousSet.create(Range.open(3, 64), integers())));
  }

  public void testIntersection() {
    ContiguousSet<Integer> set = ContiguousSet.create(Range.closed(1, 3), integers());
    assertEquals(
        ImmutableSet.of(1, 2, 3),

    assertEquals(
        ImmutableSet.of(),
        ContiguousSet.create(Range.closed(-5, -1), integers())
            .intersection(ContiguousSet.create(Range.open(3, 64), integers())));
  }

  public void testIntersection() {
    ContiguousSet<Integer> set = ContiguousSet.create(Range.closed(1, 3), integers());
    assertEquals(
        ImmutableSet.of(1, 2, 3),