Artifact artifact2 = mock(Artifact.class);
        when(artifact2.getFile()).thenReturn(null);
        when(artifact2.getGroupId()).thenReturn("group1");
        when(artifact2.getArtifactId()).thenReturn("artifact2");
        when(artifact2.getExtension()).thenReturn("ext");
        when(artifact2.getClassifier()).thenReturn("classifier1");
        when(artifact2.getVersion()).thenReturn("1");
        artifacts.add(artifact2);

 * and downloads the artifact in the local repository.  This operation returns a {@link DownloadedArtifact}.
 * </p>
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface Artifact {
    /**
     * {@return a unique identifier for this artifact}.
     * The identifier is composed of groupId, artifactId, extension, classifier, and version.
     *

     *
     * @param artifact the artifact for which to get a local path
     * @return local path associated to the given artifact, or {@code null} if none
     *
     * @see org.apache.maven.api.services.LocalRepositoryManager#getPathForLocalArtifact(Session, LocalRepository, Artifact)
     */
    Path getPathForLocalArtifact(@Nonnull Artifact artifact);

    /**
     * Gets the relative path for an artifact cached from a remote repository.

~~ specific language governing permissions and limitations
~~ under the License.

 ---
 Legacy Artifact Handlers Reference
 ---
 Hervé Boutemy
 ---
 2013-08-02
 ---

Legacy Artifact Handlers Reference

  Maven 3 artifact handlers (see {{{../../compat/maven-artifact/apidocs/org/apache/maven/artifact/handler/ArtifactHandler.html} API}})

    }

    /**
     * Gets the artifacts that make up the plugin's class realm, excluding artifacts shadowed by the Maven core realm
     * like {@code maven-project}.
     *
     * @return The plugin artifacts, never {@code null}.
     */
    public List<Artifact> getArtifacts() {
        return artifacts;
    }

    public void setArtifacts(List<Artifact> artifacts) {
        this.artifacts = artifacts;

    @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<>();

            for (Dependency dependency : dependencies) {
                Artifact artifact = createDependencyArtifact(dependency);
                if (!artifacts.containsKey(artifact.getDependencyConflictId())) {
                    artifacts.put(artifact.getDependencyConflictId(), artifact);
                }
            }

            for (Artifact artifact : artifacts.values()) {
                try {

            LOGGER.error("Error while copying artifact " + artifact + " to project local repository.", e);
        }
    }

    private Path getArtifactPath(Artifact artifact) {
        String groupId = artifact.getGroupId();
        String artifactId = artifact.getArtifactId();
        String version = artifact.getBaseVersion();
        String classifier = artifact.getClassifier();

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

  <build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.modello</groupId>
        <artifactId>modello-maven-plugin</artifactId>
        <configuration>

                }
            }
        }

        // ArtifactId is required and cannot be inherited
        if (artifactId == null || artifactId.isEmpty()) {
            context.debug("Cannot determine artifactId for POM");
            return null;
        }

        // GroupId and version can be inherited, but if still null, we can't create a valid Artifact