def METHOD_NAME(self, soup: BeautifulSoup) -> Optional[Tag]:
    """
    Finds the element that contains the exercise content. Returns `None` if
    not found.
    """
    # The exercise content element may be identified by a number of
    # different ids or classes
    exercise_element = soup.find(id=['exercise', 'aplus', 'chapter'])
    if not isinstance(exercise_element, Tag):
        exercise_element = soup.find({'class': 'entry-content'})
    if not isinstance(exercise_element, Tag):
        exercise_element = soup.body
    return exercise_element