# Classes as Dependencies

Before diving deeper into the **Dependency Injection** system, let's upgrade the previous example.

## A `dict` from the previous example

In the previous example, we were returning a `dict` from our dependency ("dependable"):

//// tab | Python 3.10+

```Python hl_lines="9"
{!> ../../docs_src/dependencies/tutorial001_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="11"

class HTTPBasic(HTTPBase):
    """
    HTTP Basic authentication.

    ## Usage

    Create an instance object and use that object as the dependency in `Depends()`.

    The dependency result will be an `HTTPBasicCredentials` object containing the
    `username` and the `password`.

    Read more about it in the

  <version>1.0-SNAPSHOT</version>
  <name>simple-project</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
  <properties>
    <environment>development</environment>
  </properties>

# Dependencies in path operation decorators

In some cases you don't really need the return value of a dependency inside your *path operation function*.

Or the dependency doesn't return a value.

But you still need it to be executed/solved.

For those cases, instead of declaring a *path operation function* parameter with `Depends`, you can add a `list` of `dependencies` to the *path operation decorator*.

  <description>Maven 4 API - CLI.</description>

  <dependencies>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-api-meta</artifactId>
    </dependency>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-api-core</artifactId>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>

  <dependencies>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-api-model</artifactId>
      <version>4.0.0-alpha-1-SNAPSHOT</version>
    </dependency>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-xml</artifactId>
      <version>4.0.0-alpha-1-SNAPSHOT</version>
    </dependency>
  </dependencies>

  <build>
    <plugins>

  <artifactId>maven-api-xml</artifactId>
  <name>Maven 4 API :: XML</name>
  <description>Maven 4 API - Immutable XML.</description>

  <dependencies>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-api-meta</artifactId>
    </dependency>
  </dependencies>

    <artifactId>maven-api</artifactId>
    <version>4.0.0-beta-6-SNAPSHOT</version>
  </parent>

  <artifactId>maven-api-di</artifactId>
  <name>Maven 4 API :: Dependency Injection</name>
  <description>Maven 4 API - Dependency Injection</description>

  <properties>
    <maven.compiler.proc>none</maven.compiler.proc>
  </properties>

  <description>Test the use of a system scoped dependency to a (fake) tools.jar.</description>

  <dependencies>
    <dependency>
      <groupId>com.sun</groupId>
      <artifactId>tools</artifactId>
      <version>1.4.2</version>
      <scope>system</scope>
      <systemPath>${jre.home}/../lib/tools.jar</systemPath>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>

///

## Settings in a dependency

In some occasions it might be useful to provide the settings from a dependency, instead of having a global object with `settings` that is used everywhere.

This could be especially useful during testing, as it's very easy to override a dependency with your own custom settings.

### The config file