An example of how Marker interfaces are resolved can be found at the link below:
here is a snippet from the same link
When you implement Serializable, you don't even have to implement any new methods because Serializable doesn't declare any. So then what good does implementing Serializable do? Serializable does not implement or declare a class's serializable behavior; the default implementation for that behavior is already implemented by ObjectOutputStream.defaultWriteObject() and ObjectInputStream.defaultReadObject(). (It would have just been easier to put this code in Object as default implementations of readObject(ObjectInputStream) and writeObject(ObjectOutputStream) that subclasses could override or extend.................