How to synchronize remove

    List<T> members;
    SortedListHandler<T> membersHandler;

    Collection<LayeredSortedQueue<T, K>> memberQueues;

    Lambda<T, K> keyGetter;

    @Override
    public boolean add(T e)
    {
        membersHandler.Insert(members, e);
        return true;
    }

    @Override
    public boolean offer(T e)
    { return add(e); }

    @Override
    public T remove()
    {
        LayeredSortedQueue<T, K> currentFrom = null;
        T current = null;

        if(!members.isEmpty())
            current = members.get(0);

        for(LayeredSortedQueue<T, K> i : memberQueues)
        {
            if(current == null || keyGetter.getMember(i.peek()).compareTo(keyGetter.getMember(current)) < 0)
            {
                currentFrom = i;
                current = i.peek();
            }
        }

        if(currentFrom == null)
            return members.remove(0);
        else
            return currentFrom.remove();
    }