tm, err := time.Parse(time.RFC3339Nano, string(val))
			if err == nil {
				j.DeleteMarker.MetaSys[ReservedMetadataPrefixLower+ReplicationTimestamp] = []byte(tm.UTC().Format(time.RFC3339Nano))
			}
		}
		if val, ok := j.DeleteMarker.MetaSys[ReservedMetadataPrefixLower+ReplicaTimestamp]; ok {
			tm, err := time.Parse(time.RFC3339Nano, string(val))
			if err == nil {

- **Deploy to FastAPI Cloud** - One-click deployment of your app to [FastAPI Cloud](https://fastapicloud.com/).
- **Stream Application Logs** - Real-time log streaming from your FastAPI Cloud-deployed application with level filtering and text search.

    }
    entry = cacheEntry2;
    if (entry != null && entry.key == key) {
      // Promote second cache entry to first so the access pattern
      // [K1, K2, K1, K3, K1, K4...] still hits the cache half the time.
      addToCache(entry);
      return entry.value;
    }
    return null;
  }

  @Override
  void clearCache() {
    super.clearCache();
    cacheEntry1 = null;
    cacheEntry2 = null;
  }

   * node(s), consider using {@link #forTree(SuccessorsFunction)} instead.
   *
   * <p><b>Performance notes</b>
   *
   * <ul>
   *   <li>Traversals require <i>O(n)</i> time (where <i>n</i> is the number of nodes reachable from
   *       the start node), assuming that the node objects have <i>O(1)</i> {@code equals()} and
   *       {@code hashCode()} implementations. (See the <a

public class ParallelDetector {

    private static Integer _defaultParallel = null;

    public static int findDefaultParallel(Project project) {
        // Since it costs IO to compute this, and is done at configuration time we want to cache this if possible
        // It's safe to store this in a static variable since it's just a primitive so leaking memory isn't an issue
        if (_defaultParallel == null) {

你可以在任何*路径操作*接收 `request` 之前，添加要与该 `request` 一起运行的代码。

也可以在生成 `response` 之后、返回之前添加代码。

例如，你可以添加一个自定义请求头 `X-Process-Time`，其值为处理请求并生成响应所花费的秒数：

{* ../../docs_src/middleware/tutorial001_py310.py hl[10,12:13] *}

/// tip

这里我们使用 [`time.perf_counter()`](https://docs.python.org/3/library/time.html#time.perf_counter) 而不是 `time.time()`，因为在这类场景中它可能更精确。🤓

///

## 多个中间件的执行顺序 { #multiple-middleware-execution-order }

## Create a Virtual Environment { #create-a-virtual-environment }

When you start working on a Python project **for the first time**, create a virtual environment **<dfn title="there are other options, this is a simple guideline">inside your project</dfn>**.

/// tip

You only need to do this **once per project**, not every time you work.

///

//// tab | `venv`

		}
	}

	var times []time.Time
	if err := DB.Model(User{}).Where("name like ?", "pluck-user%").Pluck("created_at", &times).Error; err != nil {
		t.Errorf("got error when pluck time: %v", err)
	}

	for idx, tv := range times {
		AssertEqual(t, tv, users[idx].CreatedAt)
	}

	var ptrtimes []*time.Time

		Transport: &http.Transport{
			Proxy: http.ProxyFromEnvironment,
			DialContext: (&net.Dialer{
				Timeout:   3 * time.Second,
				KeepAlive: 5 * time.Second,
			}).DialContext,
			ResponseHeaderTimeout: 3 * time.Second,
			TLSHandshakeTimeout:   3 * time.Second,
			ExpectContinueTimeout: 3 * time.Second,
			TLSClientConfig: &tls.Config{
				RootCAs: args.rootCAs,
			},

To do this, use `yield` instead of `return`, and write the extra steps (code) after.

/// tip

Make sure to use `yield` one single time per dependency.

///

/// note | Technical Details

Any function that is valid to use with:

* [`@contextlib.contextmanager`](https://docs.python.org/3/library/contextlib.html#contextlib.contextmanager) or