public CategoryToolTipGenerator getToolTipGenerator() {
        return this.toolTipGenerator;
    }

    /**
     * Sets the tool tip generator for the plot and sends a
     * {@link PlotChangeEvent} to all registered listeners.
     *
     * @param generator  the generator (<code>null</code> permitted).
     *
     * @see #getToolTipGenerator()
     *
     * @since 1.0.2
     */
    public void setToolTipGenerator(CategoryToolTipGenerator generator) {
        this.toolTipGenerator = generator;
        fireChangeEvent();
    }

    /**
     * Returns the URL generator for the plot.
     *
     * @return The URL generator (possibly <code>null</code>).
     *
     * @see #setURLGenerator(CategoryURLGenerator)
     *
     * @since 1.0.2
     */
    public CategoryURLGenerator getURLGenerator() {
        return this.urlGenerator;
    }

    /**
     * Sets the URL generator for the plot and sends a
     * {@link PlotChangeEvent} to all registered listeners.
     *
     * @param generator  the generator (<code>null</code> permitted).
     *
     * @see #getURLGenerator()
     *
     * @since 1.0.2
     */
    public void setURLGenerator(CategoryURLGenerator generator) {
        this.urlGenerator = generator;
        fireChangeEvent();