this.source = requireNonNull(source, "source");
        this.coreExtensions = requireNonNull(coreExtensions, "coreExtensions");
    }

     * {@link CoreExtensions} is validated, but the list elements may have overlapping elements, that requires
     * some logic to sort out (like precedence).
     * <p>
     * The list of {@link CoreExtensions} if present, is in precedence order.
     *
     * @return an {@link Optional} containing the {@link CoreExtensions}, or empty if not configured
     */
    @Nonnull

  xml.namespace="http://maven.apache.org/EXTENSIONS/${version}"
  xml.schemaLocation="https://maven.apache.org/xsd/core-extensions-${version}.xsd">

  <id>core-extensions</id>
  <name>CoreExtensions</name>
  <description><![CDATA[
  <p>This is a reference for the Core Extensions descriptor.</p>
  <p>The default location for the Core Extensions descriptor file is <code>${maven.projectBasedir}/.mvn/extensions.xml</code></p>

 *   <li>{@link org.apache.maven.api.cli.Options} - Represents Maven configuration options</li>
 *   <li>{@link org.apache.maven.api.cli.extensions.CoreExtensions} - Manages Maven core extensions</li>
 * </ul>
 *
 * <p>Core extensions can be configured through {@code .mvn/extensions.xml} in the project base directory
 * to enhance Maven's capabilities during build execution.</p>
 *