property.addAll(supplierWithProducer(task2))
        property.add(supplierWithProducer(task3))

        expect:
        assertHasProducer(property, task1, task2, task3)

        property.attachProducer(owner(producer))
        assertHasProducer(property, producer)
    }

    def "cannot set to empty list after value finalized"() {
        given:
        def property = property()

        property.putAll(supplierWithProducer(task2))
        property.put('a', supplierWithProducer(task3, '1'))

        expect:
        assertHasProducer(property, task1, task2, task3)

        property.attachProducer(owner(producer))
        assertHasProducer(property, producer)
    }

    def "cannot set to empty map after value finalized"() {
        given:
        property.set(someValue())