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

```xml
<dependency>
  <groupId>com.google.guava</groupId>
  <artifactId>guava-testlib</artifactId>
  <version>33.5.0-jre</version>
  <scope>test</scope>
</dependency>
```

To add a dependency using Gradle:

```gradle
dependencies {

        assertViolations(result, 0, 0, 2);

        assertContains(
                result.getWarnings().get(0),
                "'dependencies.dependency.exclusions.exclusion.groupId' for gid:aid:jar is missing");
        assertContains(
                result.getWarnings().get(1),
                "'dependencies.dependency.exclusions.exclusion.artifactId' for gid:aid:jar is missing");
    }

	</build>
	<dependencies>
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-api</artifactId>
			<version>2.0.16</version>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>commons-logging</groupId>
			<artifactId>commons-logging</artifactId>
			<version>1.3.5</version>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>junit</groupId>

  <artifactId>aid</artifactId>
  <groupId>gid</groupId>
  <version>0.1</version>

  <dependencies>
    <dependency>
      <groupId>test</groupId>
      <artifactId>a</artifactId>
      <version>0.2</version>
      <scope>system</scope>
      <systemPath>${basedir}/lib/a.jar</systemPath>
    </dependency>
    <dependency>
      <groupId>test</groupId>
      <artifactId>b</artifactId>
      <version>0.1</version>

        // check all transitive deps of a provided dependency are provided scope, except for test
        checkGroupIdScope(project, "provided", "maven-test-provided");
        artifact = getArtifact(project, "maven-test-provided", "scope-runtime");
        assertEquals("provided", artifact.getScope(), "Check scope");

        // check all transitive deps of a runtime dependency are runtime scope, except for test

  <groupId>gid</groupId>
  <version>0.1</version>

  <dependencies>
    <dependency>
      <groupId>test</groupId>
      <artifactId>a</artifactId>
      <version>0.2</version>
      <scope>system</scope>
      <systemPath>should-use-variables-and-not-hard-code-this-path</systemPath>
    </dependency>
    <dependency>
      <groupId>test</groupId>
      <artifactId>b</artifactId>
      <version>0.1</version>

    }

    private boolean areAllDependenciesInReactor(
            Collection<MavenProject> projects, Collection<Dependency> dependencies) {
        Set<String> projectKeys = getReactorProjectKeys(projects);

        for (Dependency dependency : dependencies) {
            org.eclipse.aether.artifact.Artifact a = dependency.getArtifact();
            String key = ArtifactUtils.key(a.getGroupId(), a.getArtifactId(), a.getVersion());

        Element dependency = insertNewElement(DEPENDENCY, dependenciesElement);
        addGAVElements(dependency, groupId, artifactId, version);
        return dependency;
    }

    /**
     * Convenience method to create a plugin element with GAV.
     *
     * @param pluginsElement the plugins parent element
     * @param groupId the groupId value

    private final Map<MavenProject, Integer> order;

    private final Map<String, MavenProject> projects;

    /**
     * Creates a new project dependency graph based on the specified projects.
     *
     * @param projects The projects to create the dependency graph with
     * @throws DuplicateProjectException
     * @throws CycleDetectedException
     */

  <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>