@jonathoda spawn { //model
field this.c = 0;
assert Ctr(this.c);
on message Inc() { this.c++; }
}
spawn { //view
const ui = new UI.Anchor();
during Ctr($c) assert ui.html('body', <button>{c}</button>);
on message UI.UIEvent(ui.fragmentId, '.', 'click', $e)
send Inc();
}
