if (rightValue.isMissing()) {
                return rightValue;
            }

            return Value.present()
                .withSideEffect(SideEffect.fixedFrom(leftValue))
                .withSideEffect(SideEffect.fixedFrom(rightValue));
        }

        @Override

            if (rightValue.isMissing()) {
                return rightValue;
            }

            return Value.present()
                .withSideEffect(SideEffect.fixedFrom(leftValue))
                .withSideEffect(SideEffect.fixedFrom(rightValue));
        }

        @Override

            if (value.isMissing()) {
                return value.asType();
            }

            collector.add(value.getWithoutSideEffect(), collection);
            return Value.present().withSideEffect(SideEffect.fixedFrom(value));
        }

        @Override
        public boolean isProvidedBy(Provider<?> provider) {
            return Objects.equal(provider, this.provider);
        }

        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)

                // nullable because serialization may replace value with null, e.g. when using provider of Task
                ValueSupplier.ExecutionTimeValue.ofNullable(value).withSideEffect(sideEffect)
            }

            4.toByte() -> ValueSupplier.ExecutionTimeValue.changingValue<Any>(providerWithChangingValueCodec.run { decode() }!!.uncheckedCast())

        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)