<artifactId>foo</artifactId>
  <groupId>foo</groupId>
  <version>99.44</version>
  <packaging>bleh</packaging>
  <dependencies>
    <dependency>
      <artifactId>artifactId</artifactId>
      <version>1.0</version>
    </dependency>
  </dependencies>

  <version>99.44</version>
  <packaging>jar</packaging>

  <dependencies>
    <dependency>
      <groupId>gid</groupId>
      <artifactId>aid</artifactId>
      <version>1.0</version>
      <exclusions>
        <exclusion>
          <groupId></groupId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>

  <modelVersion>4.0.0</modelVersion>
  <artifactId>foo</artifactId>
  <groupId>foo</groupId>
  <version>99.44</version>
  <packaging>bleh</packaging>
  <dependencies>
    <dependency>
      <groupId>groupId</groupId>
      <version>1.0</version>
    </dependency>
  </dependencies>

  <artifactId>foo</artifactId>
  <groupId>foo</groupId>
  <version>99.44</version>
  <packaging>bleh</packaging>
  <dependencies>
    <dependency>
      <artifactId>artifactId</artifactId>
      <groupId>groupId</groupId>
    </dependency>
  </dependencies>

  <artifactId>foo</artifactId>
  <groupId>foo</groupId>
  <version>99.44</version>
  <packaging>bleh</packaging>
  <dependencyManagement>
    <dependencies>
      <dependency>
        <artifactId>artifactId</artifactId>
        <groupId>groupId</groupId>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <packaging>jar</packaging>

  <dependencies>
    <dependency>
      <groupId>gid</groupId>
      <artifactId>aid</artifactId>
      <version>1.0</version>
      <exclusions>
        <exclusion>
          <groupId>test?</groupId>
          <artifactId>*</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>

    <plugins>
      <plugin>
        <artifactId>maven-it-plugin</artifactId>
        <version>1.0</version>
        <dependencies>
          <dependency>
            <!-- groupId missing -->
            <artifactId>a</artifactId>
            <version>2.0</version>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>

**FastAPI** 会确保每个带有 `yield` 的依赖中的"退出代码"按正确顺序运行。

例如，`dependency_c` 可以依赖于 `dependency_b`，而 `dependency_b` 则依赖于 `dependency_a`。

{* ../../docs_src/dependencies/tutorial008_an_py39.py hl[6,14,22] *}

所有这些依赖都可以使用 `yield`。

在这种情况下，`dependency_c` 在执行其退出代码时需要 `dependency_b`（此处称为 `dep_b`）的值仍然可用。

而 `dependency_b` 反过来则需要 `dependency_a`（此处称为 `dep_a` ）的值在其退出代码中可用。

Beispielsweise kann `dependency_c` von `dependency_b` und `dependency_b` von `dependency_a` abhängen:

{* ../../docs_src/dependencies/tutorial008_an_py39.py hl[6,14,22] *}

Und alle können `yield` verwenden.

In diesem Fall benötigt `dependency_c` zum Ausführen seines Exit-Codes, dass der Wert von `dependency_b` (hier `dep_b` genannt) verfügbar ist.

  <artifactId>foo</artifactId>
  <groupId>foo</groupId>
  <version>99.44</version>
  <packaging>bleh</packaging>
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>groupId</groupId>
        <version>version</version>
      </dependency>
    </dependencies>
  </dependencyManagement>