public List getOutliers(int row, int column) {
        List result = null;
        BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                row, column);
        if (item != null) {
            result = item.getOutliers();
        }
        return result;
    }

    /**
     * Returns a list of outlier values for an item.
     * 
     * @param rowKey  the row key.
     * @param columnKey  the column key.
     * 
     * @return A list of outlier values.
     * 
     * @see #getItem(int, int)
     */
    public List getOutliers(Comparable rowKey, Comparable columnKey) {
        List result = null;
        BoxAndWhiskerItem item = (BoxAndWhiskerItem) this.data.getObject(
                rowKey, columnKey);
        if (item != null) {
            result = item.getOutliers();
        }
        return result;