}

    @Override
    public boolean add(T toAdd) {
        assertMutable("add(T)");
        assertMutableCollectionContents();
        return doAdd(toAdd, eventRegister.getAddActions());
    }

    protected <I extends T> boolean add(I toAdd, Action<? super I> notification) {
        assertMutableCollectionContents();
        return doAdd(toAdd, notification);
    }

     * The mutation validators used in DefaultConfiguration only expect to be used with add/remove methods and fail when we
     * correctly try to also prevent all/withType/etc mutation methods.
     *
     * assertMutableCollectionContents is only used by add/remove methods, but we should remove this special handling and fix
     * DefaultConfiguration and CompositeDomainObjects.
     */
    public void beforeCollectionChanges(Action<Void> action) {

            @Override
            public boolean isSatisfiedBy(T element) {
                return element.getRequired().get();
            }
        });
    }

    @Override
    protected void assertMutableCollectionContents() {
        throw new ImmutableViolationException();
    }

    @Override
    public NamedDomainObjectSet<T> getEnabled() {
        return enabled;
    }

    @Override