parentBuilder.unmanagedNode(String) { node ->
                node.addReference("child", String, node)
                node.applyToSelf(ModelActionRole.Mutate) { it.path("parent").node { it.setPrivateData(String, "value") }}
            }
        }

        expect:
        registry.realize("parent.child", String) == "value"
    }

    def "child can be made known"() {
        given: