Convert interface to super-interface : Reference Type Casting « Type Casting « SCJP

1. SCJP
2. Type Casting
3. Reference Type Casting

public class MainClass {
  public static void main(String[] argv) {
    MySubInterface sub = new MyClass();
    MyInterface i = sub;
  }
}

interface MyInterface {
  public void aMethod();
}

interface MySubInterface extends MyInterface {
  public void bMethod();

}

class MyClass implements MySubInterface {
  public void aMethod() {
  }

  public void bMethod() {
  }
}