!7

cprint {
  class A {
    swappable S x() { ret "a"; }
  }
  
  class B extends A {
    /*swappableOverride*/ S x() { ret "b" + super.x(); }
  }
  
  start-thread {
    assertEqualsVerbose("a", new A().x());
    assertEqualsVerbose("ba", new B().x());
    new B c;
    c.x = () -> "c";
    assertEqualsVerbose("c", c.x());
  }
}