if w != nil {
		// Increment the prometheus http request response histogram with API, Bucket
		bucketHTTPRequestsDuration.With(prometheus.Labels{
			"api":    api,
			"bucket": bucket,
		}).Observe(w.TTFB().Seconds())
	}

	bh.Lock()
	defer bh.Unlock()

	hstats, ok := bh.httpStats[bucket]
	if !ok {
		hstats = bucketHTTPAPIStats{
			currentS3Requests: &HTTPAPIStats{},
			totalS3Requests:   &HTTPAPIStats{},

And also after the `response` is generated, before returning it.

For example, you could add a custom header `X-Process-Time` containing the time in seconds that it took to process the request and generate a response:

```Python hl_lines="10  12-13"
{!../../docs_src/middleware/tutorial001.py!}
```

/// tip

	if e != nil {
		return psv, ErrMalformedExpires
	}

	if preSignV4Values.Expires < 0 {
		return psv, ErrNegativeExpires
	}

	// Check if Expiry time is less than 7 days (value in seconds).
	if preSignV4Values.Expires.Seconds() > 604800 {
		return psv, ErrMaximumExpires
	}

	if preSignV4Values.Date.IsZero() || preSignV4Values.Date.Equal(timeSentinel) {
		return psv, ErrMalformedPresignedDate
	}

    github_event = PartialGitHubEvent.parse_raw(contents)

    # Avoid race conditions with multiple labels
    sleep_time = random.random() * 10  # random number between 0 and 10 seconds
    logging.info(
        f"Sleeping for {sleep_time} seconds to avoid "
        "race conditions and multiple comments"
    )
    time.sleep(sleep_time)

    # Get PR
    logging.debug(f"Processing PR: #{github_event.pull_request.number}")

E também depois que a `response` é gerada, antes de retorná-la.

Por exemplo, você pode adicionar um cabeçalho personalizado `X-Process-Time` contendo o tempo em segundos que levou para processar a solicitação e gerar uma resposta:

```Python hl_lines="10  12-13"
{!../../docs_src/middleware/tutorial001.py!}
```

## Outros middlewares

  private fun drainCancelQueue(eventSource: EventSource) {
    if (cancel) {
      cancel = false
      eventSource.cancel()
    }
  }

  private fun nextEvent(): Any {
    return events.poll(10, TimeUnit.SECONDS)
      ?: throw AssertionError("Timed out waiting for event.")
  }

  fun assertExhausted() {
    assertThat(events).isEmpty()
  }

  fun assertEvent(
    id: String?,
    type: String?,

import static com.google.common.cache.TestingCacheLoaders.identityLoader;
import static com.google.common.truth.Truth.assertThat;
import static java.util.concurrent.TimeUnit.SECONDS;

import com.google.common.cache.LocalCache.LocalLoadingCache;
import com.google.common.cache.LocalCache.Segment;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;

import static com.google.common.cache.TestingCacheLoaders.identityLoader;
import static com.google.common.truth.Truth.assertThat;
import static java.util.concurrent.TimeUnit.SECONDS;

import com.google.common.cache.LocalCache.LocalLoadingCache;
import com.google.common.cache.LocalCache.Segment;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;

		{0, "another_update_url", ""},
		{time.Hour, "", ""},
		{0 * time.Second, "my_download_url", "now"},
		{1 * time.Second, "my_download_url", "1 second before the latest release"},
		{37 * time.Second, "my_download_url", "37 seconds before the latest release"},
		{60 * time.Second, "my_download_url", "1 minute before the latest release"},
		{61 * time.Second, "my_download_url", "1 minute before the latest release"},

		// Testcase index 10

			if err != nil {
				log.Fatalf("Error reading session policy file: %v", err)
			}
			policy = string(bs)
		}
		stsOpts.Policy = policy
	}
	if expiryDuration != 0 {
		stsOpts.DurationSeconds = int(expiryDuration.Seconds())
	}
	li, err := cr.NewSTSAssumeRole(stsEndpoint, stsOpts)
	if err != nil {
		log.Fatalf("Error initializing STS Identity: %v", err)
	}

	stsEndpointURL, err := url.Parse(stsEndpoint)
	if err != nil {