static Runnable wrapAsActivity(O r) {
  if (r == null) null;
  Runnable r2 = toRunnable(r);
ifdef LeanMode
  ret r2;
endifdef
ifndef LeanMode
  O mod = dm_current_generic();
  if (mod == null) ret r2;
  ret r {
    AutoCloseable c = cast rcall enter(mod);
    temp c;
    r2.run();
  };
endifndef
}