20.2 The Interface java.lang.Cloneable

The Cloneable interface should be implemented by any class that is intended to support or override the method clone (§20.1.5).

public interface Cloneable { }

The interface Cloneable declares no methods.

I am disappointed in Japp. He has no method!
—Agatha Christie, The Mysterious Affair at Styles (1920), Chapter 8