public void setDecimals(final int DECIMALS) {
        if (null == decimals) {
            _decimals    = clamp(0, 5, DECIMALS);
            formatString = new StringBuilder("%.").append(_decimals).append("f").toString();
            redraw();
        } else {
            decimals.set(DECIMALS);
        }
    }
Defines the number of decimals that will be used to format the values in the tooltip
@param DECIMALS
src/main/java/eu/hansolo/tilesfx/chart/SunburstChart.java