To add a dependency on Guava testlib using Maven, use the following:

```xml
<dependency>
  <groupId>com.google.guava</groupId>
  <artifactId>guava-testlib</artifactId>
  <version>33.4.8-jre</version>
  <scope>test</scope>
</dependency>
```

To add a dependency using Gradle:

```gradle
dependencies {

It is designed to be very simple to use, and to make it very easy for any developer to integrate other components with **FastAPI**.

## What is "Dependency Injection" { #what-is-dependency-injection }

And then **FastAPI** will call that override instead of the original dependency.

{* ../../docs_src/dependency_testing/tutorial001_an_py310.py hl[26:27,30] *}

/// tip

You can set a dependency override for a dependency used anywhere in your **FastAPI** application.

    </dependency>
    <dependency>
      <groupId>com.google.guava</groupId>
      <artifactId>guava-tests</artifactId>
      <version>${project.version}</version>
      <classifier>tests</classifier>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.gwtproject</groupId>
      <artifactId>gwt-dev</artifactId>
      <version>${gwt.version}</version>
      <scope>provided</scope>
    </dependency>

  </description>
  <dependencies>
    <dependency>
      <groupId>com.google.guava</groupId>
      <artifactId>failureaccess</artifactId>
      <version>1.0.3</version>
    </dependency>
    <dependency>
      <groupId>com.google.guava</groupId>
      <artifactId>listenablefuture</artifactId>
      <version>9999.0-empty-to-avoid-conflict-with-guava</version>
    </dependency>
    <dependency>
      <groupId>org.jspecify</groupId>

  <dependencies>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-api-core</artifactId>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-api</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>

Es ist so konzipiert, sehr einfach zu verwenden zu sein und es jedem Entwickler sehr leicht zu machen, andere Komponenten mit **FastAPI** zu integrieren.

## Was ist „Dependency Injection“

## Segunda dependencia, "dependable" y "dependant"

Luego puedes crear otra función de dependencia (un "dependable") que al mismo tiempo declare una dependencia propia (por lo que también es un "dependant"):

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

Centrémonos en los parámetros declarados:

## Create a `get_current_user` dependency { #create-a-get-current-user-dependency }

Let's create a dependency `get_current_user`.

Remember that dependencies can have sub-dependencies?

`get_current_user` will have a dependency with the same `oauth2_scheme` we created before.

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

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