super.processRemaining(bb);
      int after = processCalled;
      assertEquals(before + 1, after); // default implementation pads and calls process()
      processCalled--; // don't count the tail invocation (makes tests a bit more understandable)
    }

    // ensures that the number of invocations looks sane
    void assertInvariants(int expectedBytes) {

I'll give you more concrete examples in the next chapters.

## Restarts

Similar to making sure your application is run on startup, you probably also want to make sure it is **restarted** after failures.

### We Make Mistakes

We, as humans, make **mistakes**, all the time. Software almost *always* has **bugs** hidden in different places. 🐛

.PHONY: binaries-test
binaries-test:
	go test ${GOBUILDFLAGS} ./tests/binary/... -v --base-dir ${TARGET_OUT} --binaries="$(RELEASE_SIZE_TEST_BINARIES)"

# istioctl-all makes all of the non-static istioctl executables for each supported OS
.PHONY: istioctl-all
istioctl-all: ${TARGET_OUT}/release/istioctl-linux-amd64 ${TARGET_OUT}/release/istioctl-linux-armv7 ${TARGET_OUT}/release/istioctl-linux-arm64 \

```
.
├── app                  # "app" is a Python package
│   ├── __init__.py      # this file makes "app" a "Python package"
│   ├── main.py          # "main" module, e.g. import app.main
│   ├── dependencies.py  # "dependencies" module, e.g. import app.dependencies
│   └── routers          # "routers" is a "Python subpackage"
│   │   ├── __init__.py  # makes "routers" a "Python subpackage"

   * (used as the reference iterator) against a {@code PeekingIterator} that *wraps* such an
   * iterator (used as the target iterator).
   *
   * <p>This IteratorTester makes copies of the master so that it can later verify that {@link
   * PeekingIterator#remove()} removes the same elements as the reference's iterator {@code
   * #remove()}.
   */

		}, idx, *client.host)
	}
	return ng.Wait()
}

var errPeerNotReachable = errors.New("peer is not reachable")

// GetLocks - makes GetLocks RPC call on all peers.
func (sys *NotificationSys) GetLocks(ctx context.Context, r *http.Request) []*PeerLocks {
	locksResp := make([]*PeerLocks, len(sys.peerClients))
	g := errgroup.WithNErrs(len(sys.peerClients))
	for index, client := range sys.peerClients {
		index := index

   * anywhere else
   */

  public void testInitialCapacity_negative() {
    MapMaker maker = new MapMaker();
    assertThrows(IllegalArgumentException.class, () -> maker.initialCapacity(-1));
  }

  // TODO(cpovirk): enable when ready (apparently after a change to our GWT emulation)
  public void xtestInitialCapacity_setTwice() {
    MapMaker maker = new MapMaker().initialCapacity(16);
    try {
      // even to the same value is not allowed

    `Headers` class offers full access to the HTTP headers.

 *  **Okio dependency added.** OkHttp now depends on
    [Okio](https://github.com/square/okio), an I/O library that makes it easier
    to access, store and process data. Using this library internally makes OkHttp
    faster while consuming less memory. You can write a `RequestBody` as an Okio
    `BufferedSink` and a `ResponseBody` as an Okio `BufferedSource`. Standard

      MapMakerInternalMap<K, V, ? extends InternalEntry<K, V, ?>, ? extends Segment<K, V, ?, ?>>
          makeMap(MapMaker maker) {
    return MapMakerInternalMap.create(maker);
  }

  private static MapMaker createMapMaker() {
    MapMaker maker = new MapMaker();
    maker.useCustomMap = true;
    return maker;
  }

  // constructor tests

  public void testDefaults() {

      MapMakerInternalMap<K, V, ? extends InternalEntry<K, V, ?>, ? extends Segment<K, V, ?, ?>>
          makeMap(MapMaker maker) {
    return MapMakerInternalMap.create(maker);
  }

  private static MapMaker createMapMaker() {
    MapMaker maker = new MapMaker();
    maker.useCustomMap = true;
    return maker;
  }

  // constructor tests

  public void testDefaults() {