```Python hl_lines="1  4"
{!> ../../docs_src/python_types/tutorial009b.py!}
```

////

#### Sử dụng `Union` hay `Optional`

If you are using a Python version below 3.10, here's a tip from my very **subjective** point of view:

Nếu bạn đang sử dụng phiên bản Python dưới 3.10, đây là một mẹo từ ý kiến rất "chủ quan" của tôi:

* 🚨 Tránh sử dụng `Optional[SomeType]`

is-into-cartoons.com
is-into-games.com
is-leet.com
is-local.org
is-lost.org
is-not-a.dev
is-not-certified.com
is-saved.org
is-slick.com
is-uberleet.com
is-very-bad.org
is-very-evil.org
is-very-good.org
is-very-nice.org
is-very-sweet.org
is-with-theband.com
is.eu.org
is.gov.pl
is.it
isa-geek.com
isa-geek.net
isa-geek.org
isa-hockeynut.com
isa.kagoshima.jp
isa.us

        assertTrue(toStringResult.contains("queryTime=500"));
        assertTrue(toStringResult.contains("partialResults=false"));
    }

    public void test_calculatePageInfo_extremeValues() {
        // Test with very large record count
        QueryResponseList qrList = new QueryResponseList(null, 0, 100, 0) {
            @Override
            public int size() {
                return 100;
            }
        };

- `kubectl alpha debug` now supports debugging nodes by creating a debugging container running in the node's host namespaces. ([#92310](https://github.com/kubernetes/kubernetes/pull/92310), [@verb](https://github.com/verb)) [SIG CLI]

    Castle is great! But it's a large dependency (6.5 MiB) and its security provider feature
    impacts VM-wide behavior.

 *  New: Reduce contention for applications that make a very high number of concurrent requests.
    Previously OkHttp used its connection pool as a lock when making changes to connections and
    calls. With this change each connection is locked independently.

- Ephemeral containers graduated to beta and are now available by default. ([#105405](https://github.com/kubernetes/kubernetes/pull/105405), [@verb](https://github.com/verb))

    ```java
        RequestBody.create(null, new byte[0]);
    ```

 * **`CertificatePinner` now supports wildcard hostnames.** As always with
   certificate pinning, you must be very careful to avoid [bricking][brick]
   your app. You'll need to pin both the top-level domain and the `*.` domain
   for full coverage.

    ```java
     client.setCertificatePinner(new CertificatePinner.Builder()

		return err
	}
	b := readBuf(buf[:12])
	if b.uint32() != f.CRC32 {
		return ErrChecksum
	}

	// The two sizes that follow here can be either 32 bits or 64 bits
	// but the spec is not very clear on this and different
	// interpretations has been made causing incompatibilities. We
	// already have the sizes from the central directory so we can
	// just ignore these.

	return nil
}

   *       simply switch over to use the JDK implementation wholesale if probable hash flooding is
   *       detected, sacrificing the compactness guarantee in very rare cases in exchange for much
   *       more reliable worst-case behavior.
   *   <li>null, if no entries have yet been added to the map
   * </ul>
   */
  private transient @Nullable Object table;

  /**

   *
   * <p>The temporary directory is created with permissions restricted to the current user or, in
   * the case of Android, the current app. If that is not possible (as is the case under the very
   * old Android Ice Cream Sandwich release), then this method throws an exception instead of
   * creating a directory that would be more accessible. (This behavior is new in Guava 32.0.0.