class ByRowSeries extends ObjectSeries<Object> {

    @Override
    public Object get(int index) {

        // make a copy of "source" to avoid race conditions
        DataFrame source = this.source;
        if (source != null) {
            int row = index / width;
            int column = index % width;
            return source.getColumn(column).get(row);
        }

        return materialize().get(index);
    }

    public  ByRowSeries(DataFrame source);

}