def expectedUnpackedValue = ["some key": "some value", "other key": "other value"]

        when:
        property.put("some key", Providers.of("some value").withSideEffect(sideEffect1))
        property.put("other key", Providers.of("other value").withSideEffect(sideEffect2))

        def value = property.calculateValue(ValueSupplier.ValueConsumer.IgnoreUnsafeRead)

        def expectedUnpackedValue = ["some value", "simple value", "other value"]

        when:
        property.add(Providers.of("some value").withSideEffect(sideEffect1))
        property.add(Providers.of("simple value"))
        property.add(Providers.of("other value").withSideEffect(sideEffect2))

        def value = property.calculateValue(ValueSupplier.ValueConsumer.IgnoreUnsafeRead)

        given:
        def property = providerWithNoValue()

        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)