public StandardXYToolTipGenerator(String formatString,
            NumberFormat xFormat, DateFormat yFormat) {
        
        super(formatString, xFormat, yFormat);
    }
    /**
     * Creates a tool tip generator using the specified date formatters.
     *
     * @param formatString  the label format string (<code>null</code> not 
     *                      permitted).
     * @param xFormat  the format object for the x values (<code>null</code> 
     *                 not permitted).
     * @param yFormat  the format object for the y values (<code>null</code> 
     *                 not permitted).
     */
    public StandardXYToolTipGenerator(String formatString,
            DateFormat xFormat, DateFormat yFormat) {
        
        super(formatString, xFormat, yFormat);