then:
        assertHasProducer(copy, task)
        assertHasNoProducer(property)
    }

    def "shallow copy does not inherit producer from the original"() {
        given:
        def task = Mock(Task)
        def property = propertyWithNoValue()
        property.attachProducer(owner(task))

        expect:
        assertHasNoProducer(property.shallowCopy())
    }

        expect:
        assertHasNoProducer(property)
        def value = property.calculateExecutionTimeValue()
        value.isMissing()
    }

    def "has no producer and fixed execution time value when element added"() {
        given:
        property.add("a")
        property.add("b")

        expect:
        assertHasNoProducer(property)

        expect:
        assertHasNoProducer(property)
        def value = property.calculateExecutionTimeValue()
        value.isMissing()
    }

    def "has no producer and fixed execution time value when element added"() {
        given:
        property.put('a', '1')
        property.put('b', '2')

        expect:
        assertHasNoProducer(property)

  - <b>
  - <c>""")
    }

    def "has no producer task and missing execution time value when property has no value"() {
        def property = propertyWithNoValue()

        expect:
        assertHasNoProducer(property)
        def value = property.calculateExecutionTimeValue()
        value.isMissing()
    }

    def "has no producer task and fixed execution time value when property has a fixed value"() {