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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 _table_to_str(self):
 # type: () -> str """Return single formatted table string. :return: str """

        _marker_line = self._marker_line()
        output = _marker_line + self._row_to_str(self.headers) + _marker_line

        for row in self._rows:
            output += self._row_to_str(row)

        output += _marker_line

        return output