Un ejemplo podría ser que tienes un proveedor de autenticación externo al que necesitas llamar.

Le envías un token y te devuelve un usuario autenticado.

Este proveedor podría estar cobrándote por cada request, y llamarlo podría tomar más tiempo adicional que si tuvieras un usuario de prueba fijo para los tests.

Probablemente quieras probar el proveedor externo una vez, pero no necesariamente llamarlo para cada test que se realice.

        source = Buffer().writeUtf8(multipart),
      )

    val partAbc = parts.nextPart()!!
    val partMno = parts.nextPart()!!

    assertFailsWith<IllegalStateException> {
      partAbc.body.request(20)
    }.also { expected ->
      assertThat(expected).hasMessage("closed")
    }

    assertThat(partMno.body.readUtf8()).isEqualTo("mnop")
    assertThat(parts.nextPart()).isNull()
  }

             * requested path. Normalize this here.
             */
            if (reqPath.charAt(consumed - 1) == '\\') {
                if (log.isDebugEnabled()) {
                    log.debug("Server consumed trailing slash of request path, adjusting");
                }
                dr.pathConsumed--;
            }

    "Strict-Transport-Security": "max-age=31536000; includeSubDomains",
    "Vary": "Origin,Accept-Encoding",
    "X-Amz-Id-2": "dd9025bab4ad464b049177c95eb6ebf374d3b3fd1af9251148b658df7ac2e3e8",
    "X-Amz-Request-Id": "17CDC1F4D7E69123",
    "X-Content-Type-Options": "nosniff",
    "X-Xss-Protection": "1; mode=block"
  },
  "tags": {
    "objectLocation": {
      "name": "hosts",
      "poolId": 1,

    #   o maskedKeyList: list of masked keys for security (NotRequired)
    #   o isEnvOnlyFloatLeft: is it environment only? (and show as float-left?) (NotRequired)
    #   o extendsPropRequest: other request name of exnteds-properties (NotRequired)
    #   o isCheckImplicitOverride: does it check implicit override? (NotRequired)
    #
    #; propertiesHtmlMap = map:{
    #    ; MaihamaEnv = map:{

### Timing Attacks

¿Pero qué es un "timing attack"?

Imaginemos que algunos atacantes están tratando de adivinar el nombre de usuario y la contraseña.

Y envían un request con un nombre de usuario `johndoe` y una contraseña `love123`.

Entonces el código de Python en tu aplicación equivaldría a algo como:

```Python
if "johndoe" == "stanleyjobson" and "love123" == "swordfish":
    ...

class SmbComNTCreateAndXTest {
    @Mock
    Configuration mockConfig;
    @Mock
    ServerMessageBlock mockAndX;
    @Mock
    CIFSContext mockContext;

    /**
     * Helper that creates a request instance with the supplied flags.
     * The other arguments are simple constants.
     */
    private SmbComNTCreateAndX createRequest(int flags, int createOptions) {

import org.apache.maven.api.annotations.Nullable;

import static java.util.Objects.requireNonNull;

/**
 *
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface ArtifactFactoryRequest extends Request<Session> {

    String getGroupId();

    String getArtifactId();

    String getVersion();

    String getClassifier();

    String getExtension();

    String getType();

...và **FastAPI** sử dụng các khia báo để:

* **Định nghĩa các yêu cầu**: từ tham số đường dẫn của request, tham số query, headers, bodies, các phụ thuộc (dependencies),...
* **Chuyển dổi dữ liệu*: từ request sang kiểu dữ liệu được yêu cầu.
* **Kiểm tra tính đúng đắn của dữ liệu**: tới từ mỗi request:
    * Sinh **lỗi tự động** để trả về máy khác khi dữ liệu không hợp lệ.
* **Tài liệu hóa** API sử dụng OpenAPI:

An example could be that you have an external authentication provider that you need to call.

You send it a token and it returns an authenticated user.

This provider might be charging you per request, and calling it might take some extra time than if you had a fixed mock user for tests.

You probably want to test the external provider once, but not necessarily call it for every test that runs.