when:
        def result = toList(container)

        then:
        result == iterationOrder(b, a, d, c)

        and:
        1 * provider1.calculateValue(_) >> ValueSupplier.Value.of(a)
        1 * provider2.calculateValue(_) >> ValueSupplier.Value.of(d)
        0 * _
    }

    def "provider for iterable of elements is queried when elements iterated and insertion order is retained"() {

        then:
        1 * valueProvider.calculateValue(_) >> ValueSupplier.Value.of(['k1': 'v1'])
        1 * putProvider.calculateValue(_) >> ValueSupplier.Value.of('v2')
        1 * putAllProvider.calculateValue(_) >> ValueSupplier.Value.of(['k3': 'v3'])
        0 * _

        when:
        property.getOrNull()
        then:
        1 * valueProvider.calculateValue(_) >> ValueSupplier.Value.of(['k1': 'v1'])

        then:
        1 * valueProvider.calculateValue(_) >> ValueSupplier.Value.of(["1"])
        1 * addProvider.calculateValue(_) >> ValueSupplier.Value.of("2")
        1 * addAllProvider.calculateValue(_) >> ValueSupplier.Value.of(["3"])
        0 * _

        when:
        property.getOrNull()

        then:
        1 * valueProvider.calculateValue(_) >> ValueSupplier.Value.of(["1"])

        when:
        def sideEffect = Mock(ValueSupplier.SideEffect)
        def providerWithSideEffect = Providers.of(someValue()).withSideEffect(sideEffect)
        // `PropertyInternal` does not directly provide these setters,
        // but all user-facing interfaces and their implementations do.
        property."$setter"(providerWithSideEffect)

        property.calculateValue(ValueSupplier.ValueConsumer.IgnoreUnsafeRead)