sbool cleanUp_interruptThreads; // experimental

static void cleanUp(O c) {
  if (c == null) ret;
  if (c instanceof Collection) { cleanUp((Collection) c); ret; }
  if (c instanceof Map) {
    for (O o : keys((Map) c)) cleanUp(o);
    for (O o : values((Map) c)) cleanUp(o);
    ((Map) c).clear();
    ret;
  }
  //if (!(c instanceof Class)) ret;
  
  pcall {
    // revoke license
    
    callOpt(c, 'licensed_off);
    setOpt(c, cleaningUp_flag := true);
    
    // unpause
    
    setOpt(c, "ping_pauseAll", false);
    
    // call custom cleanMeUp() and cleanMeUp_*() functions
    
    if (!isFalse(pcallOpt(c, "cleanMeUp")))
      for (S name : sorted(methodsStartingWith(c, "cleanMeUp_")))
        pcallOpt(c, name);
        
    // Java spec says finalize should only be called by GC,
    // but we care to differ.
    pcallOpt(c, "finalize");

    // remove all virtual bots (hope this works)
    
    L androids = (L) getOpt(c, "record_list");
    for (O android : unnull(androids))
      pcallOpt(android, "dispose"); // heck we'll dispose anything

    // sub-cleanup
    
    L<WeakReference> classes = cast getOpt(c, "hotwire_classes");
    if (classes != null)
      for (WeakReference cc : classes) pcall {
        cleanUp(cc.get());
      }
      
    // interrupt all threads (experimental, they might be doing cleanup?)
    
    if (cleanUp_interruptThreads)
      interruptThreads(registeredThreads(c));
  }
  
  setOpt(c, cleaningUp_flag := false);
 }

static void cleanUp(Collection l) {
  if (l == null) ret;
  for (O c : l)
    cleanUp(c);
  l.clear();
}