public void addSeries(MatrixSeries series) {
        // check arguments...
        if (series == null) {
            throw new IllegalArgumentException("Cannot add null series.");
        }
        // FIXME: Check that there isn't already a series with the same key

        // add the series...
        this.seriesList.add(series);
        series.addChangeListener(this);
        fireDatasetChanged();