我们将在主 `FastAPI` 应用中包含该 `APIRouter`，但首先，让我们来看看依赖项和另一个 `APIRouter`。

## 依赖项

我们了解到我们将需要一些在应用程序的好几个地方所使用的依赖项。

因此，我们将它们放在它们自己的 `dependencies` 模块（`app/dependencies.py`）中。

现在我们将使用一个简单的依赖项来读取一个自定义的 `X-Token` 请求首部：

```Python hl_lines="1  4-6" title="app/dependencies.py"
{!../../docs_src/bigger_applications/app/dependencies.py!}
```

/// tip

我们正在使用虚构的请求首部来简化此示例。

pkg go/build, type Directive struct #56986
pkg go/build, type Directive struct, Pos token.Position #56986
pkg go/build, type Directive struct, Text string #56986
pkg go/build, type Package struct, Directives []Directive #56986
pkg go/build, type Package struct, TestDirectives []Directive #56986
pkg go/build, type Package struct, XTestDirectives []Directive #56986
pkg go/token, method (*File) Lines() []int #57708

  - This changes the tokens provided to containers at `/var/run/secrets/kubernetes.io/serviceaccount/token` to be time-limited, auto-refreshed, and invalidated when the containing pod is deleted.
  - Clients should reload the token from disk periodically (once per minute is recommended) to ensure they continue to use a valid token. `k8s.io/client-go` version v11.0.0+ and v0.15.0+ reload tokens automatically.

errors.failed_to_download_mapping_file = No se pudo descargar el archivo de mapeo.
errors.failed_to_upload_mapping_file = No se pudo cargar el archivo de mapeo.
errors.invalid_kuromoji_token={0} no es un token válido.
errors.invalid_kuromoji_segmentation=El número de divisiones de {0} no coincide con el número de divisiones de {1}.
errors.invalid_str_is_included = {1} no es válido en {0}.
errors.blank_password = Se requiere contraseña.

func parsePAXRecord(s string) (k, v, r string, err error) {
	// The size field ends at the first space.
	nStr, rest, ok := strings.Cut(s, " ")
	if !ok {
		return "", "", s, ErrHeader
	}

	// Parse the first token as a decimal integer.
	n, perr := strconv.ParseInt(nStr, 10, 0) // Intentionally parse as native int
	if perr != nil || n < 5 || n > int64(len(s)) {
		return "", "", s, ErrHeader
	}

 *
 * <p>A high-quality hash function strives for some subset of the following virtues:
 *
 * <ul>
 *   <li><b>collision-resistant:</b> while the definition above requires making at least <i>some</i>
 *       token attempt, one measure of the quality of a hash function is <i>how well</i> it succeeds
 *       at this goal. Important note: it may be easy to achieve the theoretical minimum collision

 *
 * <p>A high-quality hash function strives for some subset of the following virtues:
 *
 * <ul>
 *   <li><b>collision-resistant:</b> while the definition above requires making at least <i>some</i>
 *       token attempt, one measure of the quality of a hash function is <i>how well</i> it succeeds
 *       at this goal. Important note: it may be easy to achieve the theoretical minimum collision

			Key:   target.NATSUserCredentials,
			Value: cfg.UserCredentials,
		},
		config.KV{
			Key:   target.NATSPassword,
			Value: cfg.Password,
		},
		config.KV{
			Key:   target.NATSToken,
			Value: cfg.Token,
		},
		config.KV{
			Key:   target.NATSNKeySeed,
			Value: cfg.NKeySeed,
		},
		config.KV{
			Key:   target.NATSCertAuthority,
			Value: cfg.CertAuthority,
		},
		config.KV{

    @Test
    public void testFilterWithHeaderUpdatesClient() {
        final Client mockNewClient = mock(Client.class);
        final Map<String, String> headers = new HashMap<>();
        headers.put("Authorization", "Bearer token");

        when(mockClient.filterWithHeader(headers)).thenReturn(mockNewClient);

        final Client result = fesenClient.filterWithHeader(headers);

        assertSame(fesenClient, result); // Should return this

    /** The key of the configuration. e.g. 60 */
    String API_ACCESS_TOKEN_LENGTH = "api.access.token.length";

    /** The key of the configuration. e.g. false */
    String API_ACCESS_TOKEN_REQUIRED = "api.access.token.required";

    /** The key of the configuration. e.g.  */
    String API_ACCESS_TOKEN_REQUEST_PARAMETER = "api.access.token.request.parameter";

    /** The key of the configuration. e.g. Radmin-api */