* same class realm is used to load build extensions and load mojos for extensions=true plugins.
     * </p>
     * <strong>Note:</strong> This is part of internal implementation and may be changed or removed without notice
     *
     * @since 3.3.0
     */
    public static final String KEY_EXTENSIONS_REALMS = DefaultMavenPluginManager.class.getName() + "/extensionsRealms";

        if (build != null) {
            for (Extension extension : build.getExtensions()) {
                Plugin plugin = new Plugin();
                plugin.setGroupId(extension.getGroupId());
                plugin.setArtifactId(extension.getArtifactId());
                plugin.setVersion(extension.getVersion());
                XmlNode configuration = extension.getDelegate().getConfiguration();

    }

    private static String getKey(Plugin plugin, boolean extension) {
        String version = ArtifactUtils.toSnapshotVersion(plugin.getVersion());
        return (extension ? "extension>" : "plugin>") + plugin.getGroupId() + ":" + plugin.getArtifactId() + ":"
                + version;
    }

 *   <li>graphs whose edges have associated values
 * </ul>
 *
 * <p>{@code ValueGraph}, as a subtype of {@code Graph}, explicitly does not support parallel edges,
 * and forbids implementations or extensions with parallel edges. If you need parallel edges, use
 * {@link Network}. (You can use a positive {@code Integer} edge value as a loose representation of

        repositoryRequest.setRemoteRepositories(getPluginArtifactRepositories());

        // prime realm cache
        MavenSession session = createMavenSession(getProject("project-with-build-extensions-plugin"));
        MavenProject project = session.getCurrentProject();
        Plugin plugin = project.getPlugin("org.apache.maven.its.plugins:maven-it-plugin");

        }

        for (MavenProject project : projects) {
            // MNG-1911 / MNG-5572: Building plugins with extensions cannot be part of reactor
            for (Plugin plugin : project.getBuildPlugins()) {
                if (plugin.isExtensions()) {
                    String pluginKey =
                            ArtifactUtils.key(plugin.getGroupId(), plugin.getArtifactId(), plugin.getVersion());

            mergePlugin_ArtifactId(builder, target, source, sourceDominant, context);
            mergePlugin_Version(builder, target, source, sourceDominant, context);
            mergePlugin_Extensions(builder, target, source, sourceDominant, context);
            mergePlugin_Executions(builder, target, source, sourceDominant, context);
            mergePlugin_Dependencies(builder, target, source, sourceDominant, context);

 *   <li>graphs whose nodes/edges are insertion-ordered, sorted, or unordered
 * </ul>
 *
 * <p>{@code Graph} explicitly does not support parallel edges, and forbids implementations or
 * extensions with parallel edges. If you need parallel edges, use {@link Network}.
 *
 * <h3>Building a {@code Graph}</h3>
 *
 * <p>The implementation classes that {@code common.graph} provides are not public, by design. To

  /**
   * The HTTP <a href="https://tools.ietf.org/html/rfc6455">{@code Sec-WebSocket-Extensions}</a>
   * header field name.
   *
   * @since 28.0
   */
  public static final String SEC_WEBSOCKET_EXTENSIONS = "Sec-WebSocket-Extensions";
  /**
   * The HTTP <a href="https://tools.ietf.org/html/rfc6455">{@code Sec-WebSocket-Key}</a> header
   * field name.
   *

   * name extensions for Windows Media metafiles</a>.
   *
   * @since 20.0
   */
  public static final MediaType WMA_AUDIO = createConstant(AUDIO_TYPE, "x-ms-wma");

  /**
   * Windows Media metafiles. For more information, see <a
   * href="https://msdn.microsoft.com/en-us/library/windows/desktop/dd562994(v=vs.85).aspx">file
   * name extensions for Windows Media metafiles</a>.
   *