@Override
    public int compare(Cell cell0, Cell cell1) {
        if (cell0.getLeft() < cell1.getLeft()) {
            return -1;
        } else if (cell0.getLeft() > cell1.getLeft()) {
            return 1;
        } else {
            throw new IllegalStateException("Two cells in effect cannot start on the same column, so this should never happen!");
        }
    }
Compares cells using their <code>left</code> field. The cells can never be equal.

@version $Id$
@author hsivonen
src/nu/validator/checker/table/HorizontalCellComparator.java