def METHOD_NAME(self, form):
    super().METHOD_NAME(form)
    section = self.article.current_revision.content
    if not section.endswith("\n"):
        section += "\r\n\r\n"
    content = get_object_or_404(
        models.ArticleRevision,
        article=self.article,
        id=self.article.current_revision.previous_revision.id,
    ).content
    start, end = self.locate_section(self.article, content)
    if start is not None and end is not None:
        # compare saved original section with last version, so we
        # can detect if someone else changed it in the meantime
        if self.orig_section != content[start:end]:
            messages.warning(
                self.request,
                "{} {} {}".format(
                    ERROR_SECTION_CHANGED, ERROR_SECTION_UNSAVED, ERROR_TRY_AGAIN
                ),
            )
        # Include the edited section into the complete previous article
        self.article.current_revision.content = (
            content[0:start] + section + content[end:]
        )
        self.article.current_revision.save()
    else:
        # Back to the version before replacing the article with the section
        self.article.current_revision = (
            self.article.current_revision.previous_revision
        )
        self.article.save()
        messages.error(
            self.request, "{} {}".format(ERROR_ARTICLE_CHANGED, ERROR_TRY_AGAIN)
        )
    return self._redirect_to_article()