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

    /**
     * Sets the flag that controls whether or not the domain grid-lines are
     * visible.
     * <p>
     * If the flag value is changed, a {@link PlotChangeEvent} is sent to all
     * registered listeners.
     *
     * @param visible  the new value of the flag.
     *
     * @see #isDomainGridlinesVisible()
     */
    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;