this.artifactId = (artifactId != null) ? artifactId : "";
        this.version = (version != null) ? version : "";
    }

    /**
     * Creates a new exception with specified detail message.
     *
     * @param message The detail message, may be {@code null}.
     * @param groupId The group id of the unresolvable model, may be {@code null}.

      <artifactId>maven-model</artifactId>
    </dependency>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-model-builder</artifactId>
    </dependency>
    <dependency>
      <groupId>org.apache.maven</groupId>
      <artifactId>maven-settings</artifactId>
    </dependency>
    <dependency>
      <groupId>org.apache.maven</groupId>

        <artifactId>maven-core</artifactId>
        <version>${project.version}</version>
      </dependency>
      <dependency>
        <groupId>org.apache.maven</groupId>
        <artifactId>maven-embedder</artifactId>
        <version>${project.version}</version>
      </dependency>
      <dependency>
        <groupId>org.apache.maven</groupId>
        <artifactId>maven-model</artifactId>

        <artifactId>plexus-utils</artifactId>
        <version>1.0.4</version>
      </dependency>
      <dependency>
        <groupId>org.apache.maven.wagon</groupId>
        <artifactId>wagon-provider-api</artifactId>
        <version>1.0-alpha-5</version>
      </dependency>
      <dependency>
        <groupId>org.apache.maven.wagon</groupId>
        <artifactId>wagon-ssh</artifactId>

      <prefix>clean</prefix>
      <artifactId>maven-clean-plugin</artifactId>
    </plugin>
    <plugin>
      <name>Maven Integration Test Plugin</name>
      <prefix>deploy</prefix>
      <artifactId>maven-deploy-plugin</artifactId>
    </plugin>
    <plugin>
      <name>Maven Integration Test Plugin</name>
      <prefix>install</prefix>
      <artifactId>maven-install-plugin</artifactId>
    </plugin>
    <plugin>

        Map artifactMap = project.getArtifactMap();

        assertNotNull( artifactMap, "artifact-map should not be null." );
        assertEquals( 1, artifactMap.size(), "artifact-map should contain 1 element." );

        Artifact artifact = (Artifact) artifactMap.get( key );

        assertNotNull( artifact, "dependency artifact not found in map." );

<project>
  <parent>
    <artifactId>maven</artifactId>
    <groupId>org.apache.maven</groupId>
    <version>2.0</version>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.apache.maven</groupId>
  <artifactId>maven-plugin-api</artifactId>
  <name>Maven Plugin API</name>
  <version>2.0</version>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13.1</version>

    <groupId>org.apache.maven</groupId>
    <artifactId>maven-api</artifactId>
    <version>4.0.0-beta-1-SNAPSHOT</version>
  </parent>

  <artifactId>maven-api-spi</artifactId>
  <name>Maven 4 API :: SPI</name>
  <description>Maven 4 API - Maven SPI.</description>

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

    @Override
    public Collection<? extends Metadata> prepare(Collection<? extends Artifact> artifacts) {
        return Collections.emptyList();
    }

    @Override
    public Artifact transformArtifact(Artifact artifact) {
        return artifact;
    }

    @Override
    public Collection<? extends Metadata> finish(Collection<? extends Artifact> artifacts) {
        LinkedHashMap<String, PluginsMetadata> plugins = new LinkedHashMap<>();

  <modelVersion>4.0.0</modelVersion>

  <parent>
    <groupId>org.apache.maven</groupId>
    <artifactId>maven</artifactId>
    <version>4.0.0-beta-1-SNAPSHOT</version>
  </parent>

  <artifactId>maven-builder-support</artifactId>

  <name>Maven Builder Support</name>
  <description>Support for descriptor builders (model, setting, toolchains)</description>

  <dependencies>