if (MojoExecution.Source.CLI.equals(mojoExecution.getSource())) {
                Throwable cause = new IllegalStateException(
                        "Goal requires online mode for execution" + " but Maven is currently offline.");
                throw new LifecycleExecutionException(
                        messageBuilderFactory, mojoExecution, session.getCurrentProject(), cause);
            } else {

    }

    @Override
    public Node getNode(org.eclipse.aether.graph.DependencyNode node) {
        return getNode(node, false);
    }

    @Override
    public Node getNode(org.eclipse.aether.graph.DependencyNode node, boolean verbose) {
        return allNodes.computeIfAbsent(node, n -> new DefaultNode(this, n, verbose));
    }

    @Nonnull
    @Override

    /**
     * Gets the root directory of the top project, which is the parent directory containing the {@code .mvn}
     * directory or a {@code pom.xml} file with the {@code root="true"} attribute.
     * If there's no such directory, an {@code IllegalStateException} will be thrown.
     *
     * @throws IllegalStateException if the root directory could not be found
     * @see #getTopDirectory()

         * as a label for the root node of the graph in case no root dependency was specified. As such, the configured
         * root artifact is ignored if {@link #root(DependencyCoordinate)} has been set.
         *
         * @param rootArtifact the root artifact for the dependency graph, may be {@code null}
         * @return this request for chaining, never {@code null}
         */
        @Nonnull

            <![CDATA[
            A repository id or (since Maven 2.0.9) an expression matching one or many repository ids to mirror, e.g.,
            <code>central</code> or <code>*,!repo1</code>.
            <code>*</code> (since Maven 2.0.5), <code>external:*</code> (since Maven 2.0.9) and <code>external:http:*</code> (since Maven 3.8.0) have
            a special meaning: see <a href="/guides/mini/guide-mirror-settings.html">Mirror Settings</a> guide.

     *
     * @param node the dependency node
     * @param dep the dependency for the given node, or {@code null} if none
     * @param filter filter the paths accepted by the tool which will consume the path.
     * @param path the path to the dependency, or {@code null} if the dependency was null
     * @param cache cache of module information about each dependency

                && (!node.isChildOfRootNode() || node.getArtifact().getScope() == null)) {
            fireEvent(ResolutionListener.MANAGE_ARTIFACT_SCOPE, listeners, node, artifact);
            node.getArtifact().setScope(artifact.getScope());
        }

        if (Artifact.SCOPE_SYSTEM.equals(node.getArtifact().getScope())
                && (node.getArtifact().getFile() == null)
                && (artifact.getFile() != null)) {

        pd.setPluginArtifact(artifact);

        pd.setArtifacts(Collections.singletonList(artifact));
        DefaultDependencyNode node = new DefaultDependencyNode(
                new org.eclipse.aether.graph.Dependency(RepositoryUtils.toArtifact(artifact), "compile"));
        pd.setDependencyNode(node);

        MojoDescriptor md = new MojoDescriptor();
        md.setGoal("my-goal");
        md.setPluginDescriptor(pd);

     * during metadata retrieval.
     */
    int VALIDATION_LEVEL_MINIMAL = 0;

    /**
     * Denotes validation as performed by Maven 2.0. This validation level is meant as a compatibility mode to allow
     * users to migrate their projects.
     */
    int VALIDATION_LEVEL_MAVEN_2_0 = 20;

    /**
     * Denotes validation as performed by Maven 3.0. This validation level is meant for existing projects.

  <description><![CDATA[
    <p>Per-directory repository metadata <code>repository-metadata.xml</code>.</p>
    <p>A directory may represent 3 types of content: "groupId", "groupId/artifactId" or "groupId/artifactId/version".</p>
    <p>Most metadata content has a meaning when the directory represents a "groupId/artifactId" (<code>groupId</code>, <code>artifactId</code>, <code>versioning</code>)<p>]]>
  </description>
  <defaults>
    <default>