def METHOD_NAME(self, chamber=None, session=None):
    if not session:
        session = max(committee_urls["lower"].keys())
    chambers = [chamber] if chamber else ["upper", "lower"]
    for chamber in chambers:
        url = committee_urls[chamber][session]
        fn, _ = self.urlretrieve(url)
        yield from self.scrape_committees_pdf(session, chamber, fn, url)