public Object clone() throws CloneNotSupportedException {
        
        HighLowItemLabelGenerator clone 
            = (HighLowItemLabelGenerator) super.clone();

        if (this.dateFormatter != null) {
            clone.dateFormatter = (DateFormat) this.dateFormatter.clone();
        }
        if (this.numberFormatter != null) {
            clone.numberFormatter = (NumberFormat) this.numberFormatter.clone();
        }
        
        return clone;