public static <T> void shuffle(java.util.List<T> l, int maxDisplacement)
{
    if(maxDisplacement>-1)
    {
        java.util.Random rand=new java.util.Random(System.currentTimeMillis());
        java.util.List<T> latch=new java.util.LinkedList();
        for(int i=0;i<l.size();++i)
        {
            int from=java.lang.Math.max(0,i-maxDisplacement);
            int to=java.lang.Math.min(l.size(),i+maxDisplacement+1);
            java.util.List<T> sub=new java.util.LinkedList(l.subList(from,to));
            if((i-maxDisplacement>=0)&&(sub.get(0)!=null))
            {
                    T picked=sub.get(0);
                    l.set(l.indexOf(picked),null);;
                    latch.add(picked);
            }
            else
            {
                while(sub.remove(null));
                if(sub.isEmpty()==false)
                {
                    T picked=sub.get(rand.nextInt(sub.size()));
                    l.set(l.indexOf(picked),null);;
                    latch.add(picked);
                }
            }
        }
        l.clear();
        l.addAll(latch);
    }
    else
        java.util.Collections.shuffle(l);
}