# 使用yield的依赖项

FastAPI支持在完成后执行一些<abbr title='有时也被称为"退出"("exit")，"清理"("cleanup")，"拆卸"("teardown")，"关闭"("close")，"上下文管理器"("context managers")。 ...'>额外步骤</abbr>的依赖项.

为此，你需要使用 `yield` 而不是 `return`，然后再编写这些额外的步骤（代码）。

/// tip | 提示

确保在每个依赖中只使用一次 `yield`。

///

/// note | 技术细节

任何一个可以与以下内容一起使用的函数：

        runner.ensureYellow();
        writer = new SuggestIndexWriter();
    }

    @AfterClass
    public static void afterClass() throws Exception {
        runner.close();
        runner.clean();
    }

    @Before
    public void before() throws Exception {
        runner.admin().indices().prepareDelete("_all").execute().actionGet();
        runner.refresh();

        }
    }

    /**
     * Cleanup and shutdown the multi-channel manager.
     */
    public void shutdown() {
        log.info("Shutting down MultiChannelManager");

        // Close all channels
        for (String sessionId : new ArrayList<>(sessionChannels.keySet())) {
            removeChannels(sessionId);
        }

        // Shutdown thread pools
        healthCheckExecutor.shutdown();

			if err := enc.Encode(mf); err != nil {
				// client may disconnect for any reasons
				// we do not have to log this.
				return
			}
		}
		if closer, ok := enc.(expfmt.Closer); ok {
			closer.Close()
		}
	})
}

// NoAuthMiddleware no auth middle ware.
func NoAuthMiddleware(h http.Handler) http.Handler {
	return h
}

// AuthMiddleware checks if the bearer token is valid and authorized.

            if (filename != null && filename.length() > 1) {
                in = new FileInputStream(filename);
            }
            Config.load(in);
            if (in != null) {
                in.close();
            }
        } catch (final IOException ioe) {
            if (LogStream.level > 0) {
                ioe.printStackTrace(log);
            }
        }

   *
   * @param method defaults to "GET" if [body] is null, and "POST" otherwise.
   */
  constructor(
    url: HttpUrl,
    headers: Headers = headersOf(),
    // '\u0000' is a sentinel value that'll choose based on what the body is:
    method: String = "\u0000",
    body: RequestBody? = null,
  ) : this(
    Builder()
      .url(url)
      .headers(headers)
      .method(
        when {

 * provided {@code standardPutAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingNavigableMap}.
 *
 * <p>Each of the {@code standard} methods uses the map's comparator (or the natural ordering of the

 * provided {@code standardPutAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingNavigableMap}.
 *
 * <p>Each of the {@code standard} methods uses the map's comparator (or the natural ordering of the

    public CopyOptions excludeWhitespace() {
        excludesWhitespace = true;
        return this;
    }

    /**
     * Specifies the prefix.
     * <p>
     * When a prefix is specified, only properties whose names start with the prefix will be included in the copy operation.
     * Additionally, the prefix will be removed from the source property name to form the destination property name.
     * </p>
     *
     * @param prefix

                                e -> logger.warn("Failed to open index: {}", docIndex, e)));
            }, e -> logger.warn("Failed to close index: {}", docIndex, e)));
        });
        saveInfo(messages -> messages.addSuccessStartedDataUpdate(GLOBAL));
        return redirect(getClass());
    }

    /**