def reset(self):
        self.urls = {}
        self.titles = {}
        self.html_blocks = {}
        self.html_spans = {}
        self.math_spans = {}
        self.list_level = 0
        self.extras = self._instance_extras.copy()
        if "footnotes" in self.extras:
            self.footnotes = {}
            self.footnote_ids = []
            self.inline_footnote_id = 0
        if self.extras in "header-ids":
            self._count_from_header_id = {} # no `defaultdict` in Python 2.4
        if "metadata" in self.extras:
            self.metadata = {}

    # Per <https://developer.mozilla.org/en-US/docs/HTML/Element/a> "rel"
    # should only be used in <a> tags with an "href" attribute.
dataset/ETHPy150Open an0/Letterpress/code/markdown2/lib/markdown2.py/Markdown.reset/swapped operands of `in`