anchor.diff:  
       var rkc = rkp.transform(new MergeAll(3, [rku, rkd])).asBroadcastStream();
   
  -    return new ReactiveKeyboard._(target, rkp, rku, rkd, rkc,
  -        allowShiftOnlyHotKeys: allowShiftOnlyHotKeys,
  -        allowAltKeyPress: allowAltKeyPress, allowEnterKeyPress: allowEnterKeyPress, navKeys: navKeys, delKeys: delKeys);
  +    return new ReactiveKeyboard._(
  +      target,
  +      rkp,
  +      rku,
  +      rkd,
  +      rkc,
  +      allowShiftOnlyHotKeys: allowShiftOnlyHotKeys,
  +      allowAltKeyPress: allowAltKeyPress,
  +      allowEnterKeyPress: allowEnterKeyPress,
  +      navKeys: navKeys,
  +      delKeys: delKeys
  +    );
     }
   
   
  
positive.code:   };
  
  
    factory ReactiveKeyboard(
        Element target, {
          bool allowShiftOnlyHotKeys: false,
  
negative.code:         bool allowEnterKeyPress: false,
          Map<int, int> navKeys: NUM_NAV,
          List<int> delKeys: DEFAULT_DEL_KEYS
        })
    {
      var rkp = KeyboardEventStream.onKeyPress(target);
      var rku = KeyboardEventStream.onKeyUp(target);
      var rkd = KeyboardEventStream.onKeyDown(target).map((key) {
  