def compute_before_after(self):
        """Compute the list of lines before and after the proposed docstring changes.

        :return: tuple of before,after where each is a list of lines of python code.
        """
        if not self.parsed:
            self._parse()
        list_from = self.input_lines
        list_to = []
        last = 0
        for e in self.docs_list:
            start, end = e['location']
            if start <= 0:
                start, end = -start, -end
                list_to.extend(list_from[last:start + 1])
            else:
                list_to.extend(list_from[last:start])
            docs = e['docs'].get_raw_docs()
            list_docs = [l + '\n' for l in docs.splitlines()]
            list_to.extend(list_docs)
            last = end + 1
        if last < len(list_from):
            list_to.extend(list_from[last:])

        return list_from, list_to
Compute the list of lines before and after the proposed docstring changes.

        :return: tuple of before,after where each is a list of lines of python code.