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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 auto_style(self):
 """ automatic styling according to _row_size 76 characters in a row """

        if self._row_size is None:
            return
        elif self._row_size == 3:
            self.set_cols_align(['l', 'l', 'l'])
            self.set_cols_valign(['t', 't', 't'])
            self.set_cols_width([12, 54, 12])
        elif self._row_size == 4:
            self.set_cols_align(['l', 'l', 'l', 'l'])
            self.set_cols_valign(['t', 't', 't', 't'])
            self.set_cols_width([10, 40, 10, 10])