The same as when declaring query parameters, when a model attribute has a default value, it is not required. Otherwise, it is required. Use `None` to make it just optional.

For example, this model above declares a JSON "`object`" (or Python `dict`) like:

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

     * parameter. The pipeType parameter should be at least one of
     * the <code>PIPE_TYPE</code> flags combined with the bitwise OR
     * operator <code>|</code>. See the examples listed above.
     */

    /**
     * Constructs an SmbNamedPipe for a specified pipe on an SMB server.
     *
     * @param url the SMB URL of the named pipe
     * @param pipeType the type of the pipe

   * configuring a {@code CacheBuilder} and building your {@link Cache} all in a single statement.
   *
   * <p><b>Warning:</b> if you ignore the above advice, and use this {@code CacheBuilder} to build a
   * cache whose key or value type is incompatible with the weigher, you will likely experience a
   * {@link ClassCastException} at some <i>undefined</i> point in the future.

   * that we choose not to make this volatile, so we do less of a "best effort" to track such
   * errors, for better performance.
   *
   * <p>For a new instance, where the arrays above have not yet been allocated, the value of {@code
   * metadata} is the size that the arrays should be allocated with. Once the arrays have been

    frame.writeInt(expectedStreamId and 0x7fffffff)
    frame.writeAll(headerBlock)

    // Check writer sends the same bytes.
    assertThat(sendHeaderFrames(false, sentHeaders)).isEqualTo(frame)

    // Reading the above frames should result in a concatenated headerBlock.
    reader.nextFrame(
      requireSettings = false,
      object : BaseTestHandler() {
        override fun headers(
          inFinished: Boolean,

      }
    ```

### Customizing Trusted Certificates ([.kt][CustomTrustKotlin], [.java][CustomTrustJava])

The full code sample shows how to replace the host platform’s certificate authorities with your own set. As above, **do not use custom certificates without the blessing of your server’s TLS administrator!**

=== ":material-language-kotlin: Kotlin"
    ```kotlin
      private val client: OkHttpClient

      init {

Here you saw how to use multiple **workers** to **parallelize** the execution of the application, take advantage of **multiple cores** in the CPU, and be able to serve **more requests**.

From the list of deployment concepts from above, using workers would mainly help with the **replication** part, and a little bit with the **restarts**, but you still need to take care of the others:

* **Security - HTTPS**
* **Running on startup**
* ***Restarts***

   * and {@code distance(end, start) == -3}. As well, {@code distance(a, a)} is always zero.
   *
   * <p>Note that this function is necessarily well-defined for any discrete type.
   *
   * @return the distance as described above, or {@link Long#MIN_VALUE} or {@link Long#MAX_VALUE} if
   *     the distance is too small or too large, respectively.
   */
  public abstract long distance(C start, C end);

  /**

      by You to the Licensor shall be under the terms and conditions of
      this License, without any additional terms or conditions.
      Notwithstanding the above, nothing herein shall supersede or modify
      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

/// tip

You would normally do this **once**, right after you create the virtual environment.

///

Make sure the virtual environment is active (with the command above) and then run:

<div class="termy">

```console
$ python -m pip install --upgrade pip

---> 100%
```

</div>

## Add `.gitignore` { #add-gitignore }