code: protected String getID(int cv, Point<Object> values) {
      String	result;
      int	i;
  
      result = "" + cv;
  
      for (i = 0; i < values.dimensions(); i++)
        result += "\t" + values.getValue(i);
  
      return result;
    }
docs: returns the ID string for a cache item.
  
  @param cv	the number of folds in the cross-validation
  @param values	the point in the space
  @return		the ID string