code: public <T> List<T> reorder( List<T> sequence)
      {
      int elementCount = sequence.size();
      if( elementCount > 1)
        {
        List<T> elements = new ArrayList<T>( sequence);
        sequence.clear();
  
        for( ; elementCount > 0; elementCount--)
          {
          sequence.add( elements.remove( generator_.nextInt( elementCount)));
          }
        }
  
      return sequence;
      }
docs: Returns the given list with its elements rearranged in a random order.