return new IdentityHashMap<>();
  }

  /**
   * Computes the difference between two maps. This difference is an immutable snapshot of the state
   * of the maps at the time this method is called. It will never change, even if the maps change at
   * a later time.
   *
   * <p>Since this method uses {@code HashMap} instances internally, the keys of the supplied maps

    return new IdentityHashMap<>();
  }

  /**
   * Computes the difference between two maps. This difference is an immutable snapshot of the state
   * of the maps at the time this method is called. It will never change, even if the maps change at
   * a later time.
   *
   * <p>Since this method uses {@code HashMap} instances internally, the keys of the supplied maps

            request: Request, call_next: Callable[[Request], Awaitable[Response]]
        ) -> Response:
            start_time = time.time()
            response = await call_next(request)
            process_time = time.time() - start_time
            response.headers["X-Process-Time"] = str(process_time)
            return response
        ```
        """

        // Test with zero
        serverData.serverTime = 0L;
        assertEquals(0L, serverData.serverTime);

        // Test with positive value
        serverData.serverTime = 132514080000000000L; // Windows file time
        assertEquals(132514080000000000L, serverData.serverTime);

        // Test with negative value
        serverData.serverTime = -1L;
        assertEquals(-1L, serverData.serverTime);

    ...
```

この場合、Python は `stanleyjobsox` と `stanleyjobson` の両方で `stanleyjobso` 全体を比較してから、文字列が同じでないと気づきます。したがって、「ユーザー名またはパスワードが正しくありません」と応答するまでに余分に数マイクロ秒かかります。

#### 応答時間が攻撃者を助ける { #the-time-to-answer-helps-the-attackers }

ここで、サーバーが「ユーザー名またはパスワードが正しくありません」というレスポンスを返すまでに、わずかに長い時間がかかったことに気づけば、攻撃者は何かしら正解に近づいた、すなわち先頭のいくつかの文字が正しかったことを知ることができます。

すると、`johndoe` よりも `stanleyjobsox` に近いものを狙って再試行できます。

            Graph graph, Graph.Vertex before, Graph.Vertex after, Collection<Lifecycle.Phase> phases) {
        // We add ordering between internal phases.
        // This would be wrong at execution time, but we are here computing a list and not a graph,
        // so in order to obtain the expected order, we add these links between phases.
        Lifecycle.Phase prev = null;
        for (Lifecycle.Phase child : phases) {

      the inputs received by the layer and the eviction policy. When this layer
      is used with an `UpdateEmbeddingCallback`, which is a time-based callback,
      the vocabulary lookup tensor is updated at the time interval set in the
      `UpdateEmbeddingCallback` based on the most up-to-date vocabulary hash
      table maintained by the layer. If this layer is not used in conjunction

    taskFaker.runNextTask()
    assertThat(log).containsExactly(
      "red:starting@0",
      "blue:starting@0",
    )
    assertThat(taskFaker.executeCallCount).isEqualTo(2)

    // Advance time until the tasks complete.
    taskFaker.advanceUntil(100.µs)
    assertThat(log).containsExactly(
      "red:starting@0",
      "blue:starting@0",
      "red:finishing@100000",
      "blue:finishing@100000",

Remember I told you before that `Annotated` can be used to add metadata to your parameters in the [Python Types Intro](../python-types.md#type-hints-with-metadata-annotations)?

Now it's the time to use it with FastAPI. 🚀

We had this type annotation:

```Python
q: str | None = None
```

What we will do is wrap that with `Annotated`, so it becomes:

```Python
q: Annotated[str | None] = None

pkg time, const ANSIC = "Mon Jan _2 15:04:05 2006"
pkg time, const April = 4
pkg time, const August = 8
pkg time, const December = 12
pkg time, const February = 2
pkg time, const Friday = 5
pkg time, const Hour = 3600000000000
pkg time, const January = 1
pkg time, const July = 7
pkg time, const June = 6
pkg time, const Kitchen = "3:04PM"
pkg time, const March = 3