<T> NamedDomainObjectList<T> newNamedDomainObjectList(Class<T> elementType);

    /**
     * Creates a {@link CompositeDomainObjectSet} for managing a collection of {@link DomainObjectCollection} of the specified type.
     */
    <T> CompositeDomainObjectSet<T> newDomainObjectSet(Class<T> elementType, DomainObjectCollection<? extends T> collection);