## Documenting the callback { #documenting-the-callback }

The actual callback code will depend heavily on your own API app.

And it will probably vary a lot from one app to the next.

It could be just one or two lines of code, like:

```Python
callback_url = "https://example.com/api/v1/invoices/events/"

    initialize the response cache.
 *  New: Fold `MockWebServerRule` into `MockWebServer`. This makes it easier to
    write JUnit tests with `MockWebServer`. The `MockWebServer` library now
    depends on JUnit, though it continues to work with all testing frameworks.
 *  Fix: `FormEncodingBuilder` is now consistent with browsers in which
    characters it escapes. Previously we weren’t percent-encoding commas,

            logger.info("");
            infoLine('-');
            String name = event.getProject().getName();
            infoMain("Skipping " + name);
            logger.info("{} was not built because a module it depends on failed to build.", name);

            infoLine('-');
        }
    }

    @Override
    public void projectStarted(ExecutionEvent event) {
        if (logger.isInfoEnabled()) {
            init();

	return ""
}

// Returns number of errors that occurred the most (incl. nil) and the
// corresponding error value. NB When there is more than one error value that
// occurs maximum number of times, the error value returned depends on how
// golang's map orders keys. This doesn't affect correctness as long as quorum
// value is greater than or equal to simple majority, since none of the equally
// maximal values would occur quorum or more number of times.

   * the already-requested ones are in service, otherwise we might create more threads than we need.
   *
   * We use [executeCallCount] and [runCallCount] to defend against starting more threads than we
   * need. Both fields are guarded by `this`.
   */
  private var executeCallCount = 0
  private var runCallCount = 0

Agora vamos usar os utilitários fornecidos pelo **FastAPI** para lidar com isso.

### `OAuth2PasswordRequestForm` { #oauth2passwordrequestform }

Primeiro, importe `OAuth2PasswordRequestForm` e use-o como uma dependência com `Depends` na *operação de rota* para `/token`:

{* ../../docs_src/security/tutorial003_an_py310.py hl[4,78] *}

`OAuth2PasswordRequestForm` é uma dependência de classe que declara um corpo de formulário com:

* O `username`.

    assertThat(Bytes.toArray(list.subList(1, 3))).isEqualTo(new byte[] {(byte) 1, (byte) 2});
    assertThat(Bytes.toArray(list.subList(2, 2))).isEqualTo(new byte[] {});
  }

  // `primitives` can't depend on `collect`, so this is what the prod code has to return.
  @SuppressWarnings("EmptyList")
  public void testAsListEmpty() {
    assertThat(Bytes.asList(EMPTY)).isSameInstanceAs(Collections.emptyList());
  }

                    proxy.getNonProxyHosts());
        }
        sessionBuilder.setProxySelector(proxySelector);

        // Note: we do NOT use WagonTransportConfigurationKeys here as Maven Core does NOT depend on Wagon Transport
        // and this is okay and "good thing".
        DefaultAuthenticationSelector authSelector = new DefaultAuthenticationSelector();
        for (Server server : request.getServers()) {

 * For other types, the converted object is created from the string representation of the source object.
 * </p>
 * <p>
 * If no pattern is specified, the pattern used for conversion depends on the locale as follows:
 * </p>
 * <table border="1">
 * <caption>Conversion Patterns</caption>
 * <tr>
 * <th>Category</th>
 * <th>Pattern</th>
 * <th>Example for {@link Locale#JAPANESE}</th>
 * </tr>

            String version = root.path("build", "plugins", "plugin", "version")
                    .map(Element::textContentTrimmed)
                    .orElse(null);

            // The exact version depends on the plugin upgrades configuration
            assertNotNull(version, "Plugin should have a version");
        }

        @Test
        @DisplayName("should not modify plugin when version is already sufficient")