public TableOrder getDataExtractOrder() {
        return this.dataExtractOrder;
    }

    /**
     * Sets the data extract order (by row or by column) and sends a
     * {@link PlotChangeEvent} to all registered listeners.
     *
     * @param order  the order (<code>null</code> not permitted).
     */
    public void setDataExtractOrder(TableOrder order) {
        if (order == null) {
            throw new IllegalArgumentException("Null 'order' argument");
        }
        this.dataExtractOrder = order;
        fireChangeEvent();
    }

    /**
     * Returns the limit (as a percentage) below which small pie sections are
     * aggregated.
     *
     * @return The limit percentage.
     */
    public double getLimit() {
        return this.limit;