void prop(Action<String> action) {
        action.execute(prop)
        prop = "called"
    }
}

class CallsMethodDuringConstruction {

    Class setAtFieldInit = getClass()
    Map<String, String> someMap = [:]
    Class setDuringConstructor

    CallsMethodDuringConstruction() {
        setDuringConstructor = setAtFieldInit
        someMap['a'] = 'b'
        assert setDuringConstructor
    }
}