misleading; it was always used to configure redirects between `https://` and
    `http://` schemes.

 *  **RouteDatabase is no longer public API.** OkHttp continues to track which
    routes have failed but this is no exposed in the API.

 *  **ResponseSource is gone.** This enum exposed whether a response came from
    the cache, network, or both. OkHttp 2 offers more detail with raw access to

- **Template Method**: `AbstractCrawlerClient`, `AbstractExtractor` - common logic with overrides
- **DI**: LastaFlute container with `@Resource` and XML config

### Core Principles

**Thread Safety**: `AtomicLong` for counters, `volatile` for status flags, synchronized blocks, thread-local storage via `CrawlingParameterUtil`

    // we should try the next route (if there is one).
    if (e is InterruptedIOException) {
      return e is SocketTimeoutException && !requestSendStarted
    }

    // Look for known client-side or negotiation errors that are unlikely to be fixed by trying
    // again with a different route.
    if (e is SSLHandshakeException) {

 *  Fix: Gracefully shut down the HTTP/2 connection before it exhausts the
    namespace of stream IDs (~536 million streams).
 *  Fix: Never pass a null `Route` to `Authenticator`. There was a bug where
    routes were omitted for eagerly-closed connections.

## Version 3.9.1

_2017-11-18_

 *  New: Recover gracefully when Android's DNS crashes with an unexpected
    `NullPointerException`.

    assertThat(response.body.string()).isEqualTo("abc")
    assertThat(server.takeRequest().exchangeIndex).isEqualTo(0)

    // Note that although we have two routes available, we only use one. The retry is permitted
    // because there are routes available, but it chooses the existing connection since it isn't
    // yet considered unhealthy.
    assertThat(server.takeRequest().exchangeIndex).isEqualTo(1)
  }

  @Test

**FastAPI** gives you the following:

### Based on open standards { #based-on-open-standards }

* [**OpenAPI**](https://github.com/OAI/OpenAPI-Specification) for API creation, including declarations of <dfn title="also known as: endpoints, routes">path</dfn> <dfn title="also known as HTTP methods, as POST, GET, PUT, DELETE">operations</dfn>, parameters, request bodies, security, etc.

		return matches[1]
	}
	return "unknown"
}

func methodNotAllowedHandler(api string) func(w http.ResponseWriter, r *http.Request) {
	return errorResponseHandler
}

// If none of the http routes match respond with appropriate errors
func errorResponseHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method == http.MethodOptions {
		return
	}

   *
   * <p>Usage example:
   *
   * {@snippet :
   * // Falling back to a zero counter in case an exception happens when processing the RPC to fetch
   * // counters.
   * ListenableFuture<Integer> faultTolerantFuture =
   *     fetchCounters().catching(FetchException.class, x -> 0, directExecutor());
   * }
   *

    private static long negativeToMaxValue(long value) {
      return (value >= 0) ? value : Long.MAX_VALUE;
    }

    /** Increments all counters by the values in {@code other}. */
    public void incrementBy(StatsCounter other) {
      CacheStats otherStats = other.snapshot();
      hitCount.add(otherStats.hitCount());
      missCount.add(otherStats.missCount());

// Update replication upload latency with a new value
func (rl *ReplicationLatency) update(size int64, duration time.Duration) {
	rl.UploadHistogram.Add(size, duration)
}

// ReplicationLastMinute has last minute replication counters
type ReplicationLastMinute struct {
	LastMinute lastMinuteLatency
}

func (rl ReplicationLastMinute) merge(other ReplicationLastMinute) (nl ReplicationLastMinute) {