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());
    assertEquals(5, immut.size());
    assertEquals(5, mut.size());
  }

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

    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());
    assertEquals(5, immut.size());
    assertEquals(5, mut.size());
  }

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

        // Short circuit for the (hopefully) majority of cases where the
        // clazz is public
        if (Modifier.isPublic(clazz.getModifiers())) {
            return methods;
        }

        // No luck - the class is not public, so we're going the longer way.
        MethodInfo[] methodInfos = new MethodInfo[methods.length];
        for (int i = methods.length; i-- > 0; ) {
            methodInfos[i] = new MethodInfo(methods[i]);