Initialize @Unmanaged property on @Managed type

test.groovy

def "Initialize @Unmanaged property on @Managed type"() {
    given:
    buildFile << """
    interface SomeThing {
        void doSomething(String param)
    }
    class DefaultSomeThing implements SomeThing {
        @Override
        public void doSomething(String param) {
            println param
        }
    }
    @Managed
    interface MyComponentSpec extends ComponentSpec {
        @Unmanaged SomeThing getSomeThing()
        void setSomeThing(SomeThing some)
    }
    class MyLanguagePlugin extends RuleSource {
        @ComponentType void registerCompType(ComponentTypeBuilder<MyComponentSpec> builder) {}
        @Defaults void initalizeStuff(ModelMap<MyComponentSpec> components) {
            components.beforeEach { component -> component.someThing = new DefaultSomeThing() }
        }
    }
    apply plugin: MyLanguagePlugin
    model {
      components {
        utils(MyComponentSpec) {
          someThing.doSomething "with that"
        }
      }
    }
    """

    when:
    succeeds "model"

    then:
    output.contains "with that"
    org.gradle.api.reporting.model.ModelReportOutput.from(output).modelNode.components.utils.someThing
}