def get_links(self, page_url: urlopen) -> None:
"""
Accepts the BeautifulSoup object passed into it, searches for all
instances other Pokedex pages (url substrings starting with pokedex-bw)
and adds each of the different substrings into a set that will be
iterated through in the `visit_page` method.
"""
poke_list: BeautifulSoup = page_url.find_all(
'option', {'value': re.compile('/pokedex-bw/[0-9]*.shtml')})
for link in poke_list:
self.pages.add(link['value'])
