private final IntegerSubscriber i2 = new IntegerSubscriber("i2");
  private final IntegerSubscriber i3 = new IntegerSubscriber("i3");
  private final ImmutableList<Subscriber> integerSubscribers =
      ImmutableList.of(
          subscriber(bus, i1, "handleInteger", Integer.class),
          subscriber(bus, i2, "handleInteger", Integer.class),

        List<Restriction> restrictions = new ArrayList<>(r1.size() + r2.size());
        Iterator<Restriction> i1 = r1.iterator();
        Iterator<Restriction> i2 = r2.iterator();
        Restriction res1 = i1.next();
        Restriction res2 = i2.next();

        boolean done = false;
        while (!done) {
            if (res1.getLowerBound() == null
                    || res2.getUpperBound() == null

    // Test & Verify
    Iterator<String> i1 = Iterables.consumingIterable(list).iterator();
    Iterator<String> i2 = Iterables.consumingIterable(list).iterator();

    i1.next();
    assertThrows(ConcurrentModificationException.class, () -> i2.next());
  }

  public void testConsumingIterable_queue_iterator() {
    List<Integer> items = ImmutableList.of(4, 8, 15, 16, 23, 42);

    // Test & Verify
    Iterator<String> i1 = Iterables.consumingIterable(list).iterator();
    Iterator<String> i2 = Iterables.consumingIterable(list).iterator();

    i1.next();
    assertThrows(ConcurrentModificationException.class, () -> i2.next());
  }

  public void testConsumingIterable_queue_iterator() {
    List<Integer> items = ImmutableList.of(4, 8, 15, 16, 23, 42);

    // Test & Verify
    Iterator<String> i1 = Iterators.consumingIterator(list.iterator());
    Iterator<String> i2 = Iterators.consumingIterator(list.iterator());

    i1.next();
    assertThrows(ConcurrentModificationException.class, () -> i2.next());
  }

  public void testIndexOf_consumedData() {
    Iterator<String> iterator = Lists.newArrayList("manny", "mo", "jack").iterator();

    // Test & Verify
    Iterator<String> i1 = Iterators.consumingIterator(list.iterator());
    Iterator<String> i2 = Iterators.consumingIterator(list.iterator());

    i1.next();
    assertThrows(ConcurrentModificationException.class, () -> i2.next());
  }

  public void testIndexOf_consumedData() {
    Iterator<String> iterator = Lists.newArrayList("manny", "mo", "jack").iterator();

a select with only <code>nil</code> channels and no default case blocks forever.
</p>

<pre>
var a []int
var c, c1, c2, c3, c4 chan int
var i1, i2 int
select {
case i1 = &lt;-c1:
	print("received ", i1, " from c1\n")
case c2 &lt;- i2:
	print("sent ", i2, " to c2\n")
case i3, ok := (&lt;-c3):  // same as: i3, ok := &lt;-c3
	if ok {
		print("received ", i3, " from c3\n")
	} else {