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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add_row(self):
 """ Return a |_Row| instance, newly added bottom-most to the table. """

        tbl = self._tbl
        tr = tbl.add_tr()
        for gridCol in tbl.tblGrid.gridCol_lst:
            tc = tr.add_tc()
            tc.width = gridCol.w
        return _Row(tr, self)