docs: def get_authenticity_token(self, url=_SIGNIN_URL):
          """ Returns an authenticity_token, mandatory for signing in """
          res = self.client._get(url=url, expected_status_code=200)
          soup = BeautifulSoup(res.text, _DEFAULT_BEAUTIFULSOUP_PARSER)
          selection = soup.select(_AUTHENTICITY_TOKEN_SELECTOR)
          try:
              authenticity_token = selection[0].get("content")
          except:
              raise ValueError(
                  "authenticity_token not found in {} with {}\n{}".format(
                   _SIGNIN_URL, _AUTHENTICITY_TOKEN_SELECTOR, res.text))
          return authenticity_token