def redent(self, tokened_lines):
        """
        Redent the given iterable of tokenized lines.

        Returns a generator which will yield redented lines.

        """

        for line in tokened_lines:
            for token in line:
                output = self.visit(token)
                if output not in None:
                    yield output

        if self.stack:
            yield self.reassemble()
dataset/ETHPy150Open Julian/Condent/condent.py/Condenter.redent/operator `is not` -> `not in`