!752

// PersistentMap is defined in #1002063

static PersistentMap<S, MyType> map;

static class MyType {
  S a;
  int b;
}

p {
  map = new PersistentMap<S, MyType>("mymap");
  new MyType x;
  x.a = "I am new";
  x.b = map.size();
  map.put("bla " + x.b, x);
  print(structure(map));
}