In that case, you can simply swap the standard `dataclasses` with `pydantic.dataclasses`, which is a drop-in replacement:

{* ../../docs_src/dataclasses_/tutorial003_py310.py hl[1,4,7:10,13:16,22:24,27] *}

1. We still import `field` from standard `dataclasses`.

2. `pydantic.dataclasses` is a drop-in replacement for `dataclasses`.

3. The `Author` dataclass includes a list of `Item` dataclasses.

...без додавання обов’язкового параметра `needy`, Ви побачите помилку:

```JSON
{
  "detail": [
    {
      "type": "missing",
      "loc": [
        "query",
        "needy"
      ],
      "msg": "Field required",
      "input": null
    }
  ]
}
```

Оскільки `needy` є обов’язковим параметром, вам потрібно вказати його в URL:

```
http://127.0.0.1:8000/items/foo-item?needy=sooooneedy
```

* Ele pode fazer algo com essa **resposta** ou executar qualquer código necessário.
* Então ele retorna a **resposta**.

/// note | Detalhes Técnicos

Se você tiver dependências com `yield`, o código de saída será executado *depois* do middleware.

    /**
     * Creates a NetBIOS session message header.
     * The header format is:
     * - Byte 0: Message type (0x00 for SESSION_MESSAGE)
     * - Byte 1: High bit of 17-bit length field
     * - Bytes 2-3: Lower 16 bits of length field
     */
    private static byte[] messageHeader(int length) {
        byte[] h = new byte[4];
        h[0] = (byte) SessionServicePacket.SESSION_MESSAGE;

  var bodyLimit: Long by delegate::bodyLimit

  var serverSocketFactory: ServerSocketFactory? by delegate::serverSocketFactory

  var dispatcher: Dispatcher = QueueDispatcher()
    set(value) {
      field = value
      delegate.dispatcher = value.wrap()
    }

  val port: Int
    get() {
      before() // This implicitly starts the delegate.
      return delegate.port
    }

  val hostName: String

    }

    if (userRequest.header("Connection") == null) {
      requestBuilder.header("Connection", "Keep-Alive")
    }

    // If we add an "Accept-Encoding: gzip" header field we're responsible for also decompressing
    // the transfer stream.
    var transparentGzip = false
    if (userRequest.header("Accept-Encoding") == null && userRequest.header("Range") == null) {
      transparentGzip = true

      this.notBefore = notBefore
      this.notAfter = notAfter
    }

    /**
     * Sets the certificate to be valid immediately and until the specified duration has elapsed.
     * The precision of this field is seconds; further precision will be truncated.
     */
    fun duration(
      duration: Long,
      unit: TimeUnit,
    ) = apply {
      val now = System.currentTimeMillis()

   * without it because it is an immutable object in a volatile field. This is desirable so that
   * methods like {@link #state}, {@link #failureCause} and notably {@link #toString} can be run
   * without grabbing the lock.
   *
   * <p>To update this field correctly the lock must be held to guarantee that the state is
   * consistent.
   */

     * Initializes the pager with default values for page size and current page number.
     */
    public ReqHeaderPager() {
        // Default constructor - initialization handled by field defaults and clear() method
    }

    /**
     * Clears all pager data and resets to default values.
     * This method resets pagination state and clears all request header fields.
     */

}

/**
 * Returns true if the response headers and status indicate that this response has a (possibly
 * 0-length) body. See RFC 7231.
 */
fun Response.promisesBody(): Boolean {
  // HEAD requests never yield a body regardless of the response headers.
  if (request.method == "HEAD") {
    return false
  }

  val responseCode = code
  if ((responseCode < HTTP_CONTINUE || responseCode >= 200) &&