* @since 4.0.0
 * @see org.apache.maven.api.services.DependencyResolverResult#getRoot()
 */
@Experimental
@Immutable
@Provider
public interface Node {

    /**
     * @return artifact for this node
     */
    @Nullable
    Artifact getArtifact();

    /**
     * @return dependency for this node
     */
    @Nullable
    Dependency getDependency();

    /**
     * Gets the child nodes of this node.

      <plugins>
        <plugin>
          <groupId>org.apache.maven.its.plugins</groupId>
          <artifactId>maven-it-plugin-class-loader</artifactId>
          <version>2.1-SNAPSHOT</version>
          <dependencies>
            <dependency>
              <groupId>org.apache.maven.its.mng3906</groupId>
              <artifactId>e</artifactId>
              <version>0.1</version>
            </dependency>
            <dependency>

<project>
  <parent>
    <artifactId>p0</artifactId>
    <groupId>maven</groupId>
    <version>1.0</version>
    <relativePath>../../pom.xml</relativePath>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  <artifactId>p1</artifactId>

specific language governing permissions and limitations
under the License.
-->

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

under the License.
-->

<project>
  <modelVersion>4.0.0</modelVersion>

  <parent>
    <groupId>org.apache.maven.its.mng3899</groupId>
    <artifactId>parent</artifactId>
    <version>0.1</version>
  </parent>

  <artifactId>child</artifactId>

  <name>Maven Integration Test :: MNG-3899</name>
  <description>
    Test that build extensions are properly merged during inheritance.
  </description>

        mojoDescriptor.setGoal("goal");
        PluginDescriptor pluginDescriptor = new PluginDescriptor();
        pluginDescriptor.setGoalPrefix("goalPrefix");
        pluginDescriptor.setArtifactId("artifactId");
        mojoDescriptor.setPluginDescriptor(pluginDescriptor);

        Parameter parameter = new Parameter();
        parameter.setType("java.lang.String[]");
        parameter.setName("toAddresses");

<project>
  <parent>
    <artifactId>p0</artifactId>
    <groupId>maven</groupId>
    <version>1.0</version>
    <relativePath>../../pom.xml</relativePath>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  <artifactId>p1</artifactId>

<project>
  <parent>
    <artifactId>p3</artifactId>
    <groupId>maven</groupId>
    <version>1.0</version>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  <groupId>maven</groupId>
  <artifactId>p4</artifactId>
  <packaging>jar</packaging>
  <name>p4</name>
  <version>1.0</version>

    }

    @Override
    public Object get(String groupId, String artifactId, String version, String tag) {
        return cache.get(session, new Key(groupId, artifactId, version, tag));
    }

    @Override
    public void put(String groupId, String artifactId, String version, String tag, Object data) {
        cache.put(session, new Key(groupId, artifactId, version, tag), data);
    }

    static class Key {

  <groupId>org.apache.maven.its.it0063</groupId>
  <artifactId>maven-it-it0063</artifactId>
  <version>1.0</version>
  <packaging>jar</packaging>

  <name>Maven Integration Test :: it0063</name>
  <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>