public ModelResolver newCopy() {
        return new ProjectModelResolver(this);
    }

    public ModelSource resolveModel(String groupId, String artifactId, String version)
            throws UnresolvableModelException {
        Artifact pomArtifact = new DefaultArtifact(groupId, artifactId, "", "pom", version);

        try {
            ArtifactRequest request = new ArtifactRequest(pomArtifact, repositories, context);

        assertTrue(value instanceof Collection);

        @SuppressWarnings("unchecked")
        Collection<Artifact> artifacts = (Collection<Artifact>) value;

        assertEquals(1, artifacts.size());

        Artifact result = artifacts.iterator().next();

        assertEquals("org.myco.plugins", result.getGroupId());
    }

    @Test

        private final String groupId;

        private final String artifactId;

        private final int hashCode;

        GAKey(String groupId, String artifactId) {
            this.groupId = (groupId != null) ? groupId : "";
            this.artifactId = (artifactId != null) ? artifactId : "";

            hashCode = Objects.hash(this.groupId, this.artifactId);
        }

        @Override

                artifact.getType(),
                artifact.getClassifier(),
                remoteRepositories,
                artifact.getDependencyTrail(),
                t);
        this.artifact = artifact;
    }

    public Artifact getArtifact() {
        return artifact;
    }

    public String getGroupId() {
        return groupId;
    }

            }

            if (!(obj instanceof CacheKey)) {
                return false;
            }

            CacheKey that = (CacheKey) obj;

            return Objects.equals(this.artifactId, that.artifactId)
                    && Objects.equals(this.groupId, that.groupId)
                    && Objects.equals(this.version, that.version)
                    && Objects.equals(this.localRepo, that.localRepo)

    /**
     * Gets the artifact id of the plugin.
     *
     * @return The artifact id of the plugin.
     */
    String getArtifactId();

    /**
     * Sets the artifact id of the plugin.
     *
     * @param artifactId The artifact id of the plugin.
     * @return This request, never {@code null}.
     */
    PluginVersionRequest setArtifactId(String artifactId);

    /**

    Artifact createArtifact(String groupId, String artifactId, String version, String packaging);

    Artifact createArtifact(String groupId, String artifactId, String version, String scope, String type);

    Artifact createProjectArtifact(String groupId, String artifactId, String version);

    Artifact createArtifactWithClassifier(

    }

    public Artifact createParentArtifact(String groupId, String artifactId, String version) {
        return createProjectArtifact(groupId, artifactId, version);
    }

    public Artifact createPluginArtifact(String groupId, String artifactId, VersionRange versionRange) {
        return createArtifact(groupId, artifactId, versionRange, "maven-plugin", null, Artifact.SCOPE_RUNTIME, null);
    }

        packagingRegistry = emptyPackagingRegistry;
    }

    private static Plugin newPlugin(String artifactId, String... goals) {
        return Plugin.newBuilder()
                .groupId("org.apache.maven.plugins")
                .artifactId(artifactId)
                .executions(Arrays.stream(goals)
                        .map(goal -> PluginExecution.newBuilder()

    VersionsMetadata(Artifact artifact, Path path, Date timestamp) {
        super(createRepositoryMetadata(artifact), path, timestamp);
        this.artifact = artifact;
    }

    private static Metadata createRepositoryMetadata(Artifact artifact) {

        Metadata.Builder metadata = Metadata.newBuilder();
        metadata.groupId(artifact.getGroupId());
        metadata.artifactId(artifact.getArtifactId());