String propertyName = propertyAccessorType.propertyNameFor(method);
                ModelPropertyExtractionContext propertyContext = propertiesMap.get(propertyName);
                if (propertyContext == null) {
                    propertyContext = new ModelPropertyExtractionContext(propertyName);
                    propertiesMap.put(propertyName, propertyContext);
                }

            return value == null ? null : value.getClass();
        }

        @Nullable
        private PropertyMutator propertyMutatorFor(String propertyName, @Nullable Class<?> valueType) {
            final Pair<String, ? extends Class<?>> key = Pair.of(propertyName, valueType);
            final PropertyMutator cached = mutators.get(key);
            if (cached != null) {
                return cached;
            }

     *
     * @param propertyName the name of the system property
     * @return the provider for the system property, never returns null
     * @since 6.1
     */
    Provider<String> systemProperty(String propertyName);

    /**
     * Creates a {@link Provider} whose value is fetched from system properties using the given property name.
     *
     * @param propertyName the name of the system property

                    @get:Input
                    val propertyName: Property<String>
                }

                override fun obtain(): String? = parameters.run {
                    propertiesFile.get().asFile.takeIf { it.isFile }?.inputStream()?.use {
                        java.util.Properties().apply { load(it) }
                    }?.get(propertyName.get()) as String?
                }
            }

            onProjectsCoupled()

            return withDelegateDynamicCallReportingConfigurationOrder(
                propertyName,
                action = { tryGetProperty(propertyName) },
                resultNotFoundExceptionProvider = { getMissingProperty(propertyName) }
            )
        }

        override fun invokeMethod(name: String, args: Any): Any? {

        work.visitOutputs(context.getWorkspace(), new UnitOfWork.OutputVisitor() {
            @Override
            public void visitOutputProperty(String propertyName, TreeType type, UnitOfWork.OutputFileValueSupplier value) {
                ensureOutput(propertyName, value.getValue(), type);
            }

            @Override
            public void visitLocalState(File localStateRoot) {

    }

    def "querying flag status notifies listener"() {
        def flag = Stub(FeatureFlag)
        flag.systemPropertyName >> propertyName

        when:
        flags.isEnabled(flag)

        then:
        1 * featureFlagListener.flagRead(flag)

        where:
        propertyName << ["prop", null]
    }

    }

    private static <T> Collection<T> extractAndValidate(String propertyName, String componentName, SetProperty<T> declared) {
        declared.finalizeValue();
        Collection<T> value = declared.get();
        assertNonEmpty(propertyName, componentName, value);
        return value;
    }

    private static void assertNonEmpty(String propertyName, String componentName, Collection<?> property) {

            for (final Map.Entry<String, Object> entry : httpClientPropertyMap.entrySet()) {
                final String propertyName = entry.getKey();
                if (beanDesc.hasPropertyDesc(propertyName)) {
                    final PropertyDesc propertyDesc = beanDesc.getPropertyDesc(propertyName);
                    propertyDesc.setValue(closeableHttpClient, entry.getValue());
                } else {

        return outer
    }
}


class Outer {
    @get:Restricted
    val inner: Inner = Inner()

    @Configuring(propertyName = "inner")
    fun configureInner(fn: Functional) {
        fn.configure(inner)
    }

    @Configuring(propertyName = "inner")
    fun configureInnerWithGeneric(fn: GenericFunctional<Inner>) {
        fn.configure(inner)
    }
}


interface Functional {