* Gets the class realm exposing the Maven 4 API. This is basically a restricted view on the Maven core realm.
     *
     * @return The class realm exposing the Maven API, never {@code null}.
     */
    ClassRealm getMaven4ApiRealm();

    /**
     * Creates a new class realm for the specified project and its build extensions.
     *
     * @param model The model of the project for which to create a realm, must not be {@code null}.