public boolean isDomainGridlinesVisible() {
        return this.domainGridlinesVisible;
    }

    /**
     * Sets the flag that controls whether or not the domain grid-lines are 
     * visible.  If the flag value is changed, a {@link PlotChangeEvent} is 
     * sent to all registered listeners.
     *
     * @param visible  the new value of the flag.
     * 
     * @see #getDomainGridlinePaint()
     */
    public void setDomainGridlinesVisible(boolean visible) {
        if (this.domainGridlinesVisible != visible) {
            this.domainGridlinesVisible = visible;
            fireChangeEvent();
        }
    }

    /**
     * Returns the stroke for the grid-lines (if any) plotted against the 
     * domain axis.
     *
     * @return The stroke (never <code>null</code>).
     * 
     * @see #setDomainGridlineStroke(Stroke)
     */
    public Stroke getDomainGridlineStroke() {
        return this.domainGridlineStroke;