abstract class Base {}

class Foo extends Base {}
class Bar extends Base {}
class Baz extends Base {}

void foo(x) {

}

void bar(x) {

}

void foo_escaped(x) {

}

void bar_escaped(x) {

}

void escape(fn) {
  fn(new Baz());
}

main() {
  foo(new Foo());
  bar(new Bar());
  escape(foo_escaped);
  escape(bar_escaped);
}