class AbstractInterfaceTest {

  public static void main(String[] args) {
    new AbstractInterfaceTest();
  }

  AbstractInterfaceTest() {
    AIAbstract ai = new AIImpl();
    ai.doIt();
  }

  interface AIInterface {
    void doIt();
  }

  abstract class AIAbstract implements AIInterface {}

  class AIImpl extends AIAbstract {
    AIImpl() {}

    public void doIt() {
      System.out.println("Success");
    }
  }

}