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),

  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),

            Iterator<Exclusion> i1 = ce1.iterator();
            Iterator<Exclusion> i2 = ce2.iterator();
            while (i1.hasNext() && i2.hasNext()) {
                if (!equals(i1.next(), i2.next())) {
                    return false;
                }
            }
            return !i1.hasNext() && !i2.hasNext();
        }
        return false;
    }

        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

@item_router.get("/")
def get_items(user_id: Optional[str] = None):
    if user_id is None:
        return [{"item_id": "i1", "user_id": "u1"}, {"item_id": "i2", "user_id": "u2"}]
    else:
        return [{"item_id": "i2", "user_id": user_id}]


@item_router.get("/{item_id}")
def get_item(item_id: str, user_id: Optional[str] = None):
    if user_id is None:
        return {"item_id": item_id}
    else:

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

    i1.next();
    try {
      i2.next();
      fail("Concurrent modification should throw an exception.");
    } catch (ConcurrentModificationException cme) {
      // Pass
    }
  }

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

    i1.next();
    try {
      i2.next();
      fail("Concurrent modification should throw an exception.");
    } catch (ConcurrentModificationException cme) {
      // Pass
    }
  }

    List<String> list = Lists.newArrayList("a", "b");

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

    i1.next();
    try {
      i2.next();
      fail("Concurrent modification should throw an exception.");
    } catch (ConcurrentModificationException cme) {
      // Pass
    }
  }

    List<String> list = Lists.newArrayList("a", "b");

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

    i1.next();
    try {
      i2.next();
      fail("Concurrent modification should throw an exception.");
    } catch (ConcurrentModificationException cme) {
      // Pass
    }
  }

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 {