anchor.diff:      _globalState.isolates.remove(id); // indicate this isolate is not active
       errorPorts.clear();
       if (doneHandlers != null) {
  -      doneHandlers.forEach((port, response) { port.send(response); });
  +      for (int i = 0; i < doneHandlers.length; i += 2) {
  +        SendPort responsePort = doneHandlers[i];
  +        Object response = doneHandlers[i + 1];
  +        responsePort.send(response);
  +      }
         doneHandlers = null;
       }
     }
  
positive.code:     INSTANCE_FROM_CLASS_ID;
  
  import 'dart:async';
  import 'dart:collection' show Queue, HashMap;
  import 'dart:isolate';
  import 'dart:_native_typed_data' show NativeByteBuffer, NativeTypedData;
  
  
negative.code: 
    void addDoneListener(SendPort responsePort, Object response) {
      if (doneHandlers == null) {
        doneHandlers = [];
      }
      for (int i = 0; i < doneHandlers.length; i += 2) {
        if (responsePort == doneHandlers[i]) {
          doneHandlers[i + 1] = response;
          return;
        }
      }
      doneHandlers.add(responsePort);
      doneHandlers.add(response);
    }
  
    void removeDoneListener(SendPort responsePort) {
      if (doneHandlers == null) return;
      for (int i = 0; i < doneHandlers.length; i += 2) {
        if (responsePort == doneHandlers[i]) {
          doneHandlers.removeRange(i, i + 2);
          return;
        }
      }
    }
  
    void setErrorsFatal(Capability authentification, bool errorsAreFatal) {
  