从关系中添加或删除解析对象时发生ConcurrentModificationException

Question

我正在尝试使用Parse创建一种最喜欢的机制。问题是，当我按addToFavIcon时，我收到一个ConcurrentModificationException，但我不知道它从哪里来。这是在关系中添加和删除的功能：

public void removeFavInParse(final Product model, final FavoriteViewHolder holder) {
    if (MainApplication.getInstance().isDeviceConnectedToInternet()) {
        if (ParseUser.getCurrentUser() != null) {
            ParseQuery<ParseObject> tiles = ParseQuery.getQuery(Config.PRODUCT_TABLE);
            tiles.getInBackground(model.getId(), new GetCallback<ParseObject>() {
                @Override
                public void done(final ParseObject object, ParseException e) {
                    ParseRelation<ParseUser> user = object.getRelation(Config.PRODUCT_WISH_USERS);
                    user.remove(ParseUser.getCurrentUser());
                    object.saveInBackground(new SaveCallback() {
                        @Override
                        public void done(ParseException e) {
                            final ParseUser user = ParseUser.getCurrentUser();
                            final ParseRelation<ParseObject> tile = user.getRelation(Config.WISHED_POSTS);
                            tile.remove(object);
                            user.saveInBackground();
                        }
                    });
                }
            });
        }
    }
}

这是错误代码：

java.util.ConcurrentModificationException
    at java.util.HashMap$HashIterator.nextEntry(HashMap.java:787)
    at java.util.HashMap$KeyIterator.next(HashMap.java:814)
    at com.parse.ParseRelationOperation.removeParseObjectFromSet(ParseRelationOperation.java:124)
    at com.parse.ParseRelationOperation.removeAllParseObjectsFromSet(ParseRelationOperation.java:136)
    at com.parse.ParseRelationOperation.mergeWithPrevious(ParseRelationOperation.java:244)
    at com.parse.ParseObject.performOperation(ParseObject.java:2966)
    at com.parse.ParseRelation.remove(ParseRelation.java:145)
    at com.peppersoft.dragonulex.adapters.FavoritesAdapter$4$1.done(FavoritesAdapter.java:169)
    at com.peppersoft.dragonulex.adapters.FavoritesAdapter$4$1.done(FavoritesAdapter.java:164)
    at com.parse.ParseTaskUtils$1.done(ParseTaskUtils.java:75)
    at com.parse.ParseTaskUtils$1.done(ParseTaskUtils.java:72)
    at com.parse.ParseTaskUtils$2$1.run(ParseTaskUtils.java:116)
    at android.os.Handler.handleCallback(Handler.java:739)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:135)
    at android.app.ActivityThread.main(ActivityThread.java:5221)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

任何人都可以减轻我的思想吗？