then:
        registry.get("values.mutable", MutableValue).value == "foo"
    }

    static class ByTypeBindingSubjectRule extends RuleSource {
        @Mutate
        void connectElementToInput(MutableValue element, Integer input) {
            element.value = input
        }
    }

    def "by-type subject bindings are scoped to the scope of an inner rule"() {
        given:

- Rule source classes must directly extend org.gradle.model.RuleSource''')
    }

    static class ElementRules extends RuleSource {
        @Mutate
        void connectElementToInput(Bean element, String input) {
            element.value = input
        }
    }

    def "inputs of a rule from an inner source are not realised if the rule is not required"() {
        given: