code: def get_ancestor_tag_names(mention):
      
      span = _to_span(mention)
      tag_names = []
      i = _get_node(span.sentence)
      while i is not None:
          tag_names.insert(0, str(i.tag))
          i = i.getparent()
      return tag_names
docs: Return the HTML tag of the Mention's ancestors.
  
      For example, ['html', 'body', 'p'].
      If a candidate is passed in, only the ancestors of its first Mention are returned.
  
      :param mention: The Mention to evaluate
      :rtype: list of strings