}

func extractMetadata(ctx context.Context, mimesHeader ...textproto.MIMEHeader) (metadata map[string]string, err error) {
	metadata = make(map[string]string)

	for _, hdr := range mimesHeader {
		// Extract all query values.
		err = extractMetadataFromMime(ctx, hdr, metadata)
		if err != nil {
			return nil, err
		}
	}

	// Set content-type to default value if it is not set.

But there could be cases where you want to be able to set parameters on the dependency, without having to declare many different functions or classes.

Let's imagine that we want to have a dependency that checks if the query parameter `q` contains some fixed content.

But we want to be able to parameterize that fixed content.

## A "callable" instance { #a-callable-instance }

///

## Pasos Previos Antes de Iniciar { #previous-steps-before-starting }

Hay muchos casos en los que quieres realizar algunos pasos **antes de iniciar** tu aplicación.

Por ejemplo, podrías querer ejecutar **migraciones de base de datos**.

Pero en la mayoría de los casos, querrás realizar estos pasos solo **una vez**.

    /** The key of the message: The specified query has an unknown condition. */
    public static final String ERRORS_invalid_query_unknown = "{errors.invalid_query_unknown}";

    /** The key of the message: The given query is invalid. */
    public static final String ERRORS_invalid_query_parse_error = "{errors.invalid_query_parse_error}";

     * This method queries the search engine for child documents and extracts their URLs.
     *
     * @param searchEngineClient the search engine client to query
     * @param id the parent document ID to find children for
     * @return a set of RequestData objects for the child URLs, or null if no children found
     */

* o corpo da resposta
* o corpo JSON
* o corpo do formulário
* o corpo do arquivo
* o corpo da função

* o parâmetro
* o parâmetro de corpo
* o parâmetro de path
* o parâmetro de query
* o parâmetro de cookie
* o parâmetro de header
* o parâmetro de formulário
* o parâmetro da função

* o evento
* o evento de inicialização
* a inicialização do servidor
* o evento de encerramento

* **Typ-Prüfungen**.

... und **FastAPI** verwendet dieselben Deklarationen, um:

* **Anforderungen** zu definieren: aus <abbr title="Request – Anfrage: Daten, die der Client zum Server sendet">Request</abbr>-Pfadparametern, Query-Parametern, Header-Feldern, Bodys, Abhängigkeiten, usw.
* **Daten umzuwandeln**: aus dem Request in den erforderlichen Typ.
* **Daten zu validieren**: aus jedem Request:

/// info | 技术细节

`Security` 实际上是 `Depends` 的子类，而且只比 `Depends` 多一个参数。

但使用 `Security` 代替 `Depends`，**FastAPI** 可以声明安全作用域，并在内部使用这些作用域，同时，使用 OpenAPI 存档 API。

但实际上，从 `fastapi` 导入的 `Query`、`Path`、`Depends`、`Security` 等对象，只是返回特殊类的函数。

///

## 使用 `SecurityScopes`

修改依赖项 `get_current_user`。

这是上面的依赖项使用的依赖项。

这里使用的也是之前创建的 OAuth2 方案，并把它声明为依赖项：`oauth2_scheme`。

	},
}

// Recycle the underlying map.
func (m *MSS) Recycle() {
	if m != nil && *m != nil {
		mssPool.Put(*m)
		*m = nil
	}
}

// ToQuery constructs a URL query string from the MSS, including "?" if there are any keys.
func (m MSS) ToQuery() string {
	if len(m) == 0 {
		return ""
	}
	var buf strings.Builder
	buf.WriteByte('?')
	keys := make([]string, 0, len(m))

import org.opensearch.action.search.SearchResponse;
import org.opensearch.common.settings.Settings;
import org.opensearch.common.xcontent.XContentType;
import org.opensearch.index.query.QueryBuilders;
import org.opensearch.search.SearchHit;
import org.opensearch.transport.client.Client;

/**
 * The AnalyzerSettings class is responsible for managing and configuring analyzers for different fields and languages.