code: def _login(self, session, get_request=False):
          
          req = session.post(self._login_url, data=self._logindata)
          if _LOGIN_ERROR_STRING in req.text or \
                  req.status_code == 403 or \
                  req.url == _LOGIN_URL:
              err_mess = "YesssSMS: login failed, username or password wrong"
  
              if _LOGIN_LOCKED_MESS in req.text:
                  err_mess += ", page says: " + _LOGIN_LOCKED_MESS_ENG
                  self._suspended = True
                  raise self.AccountSuspendedError(err_mess)
              raise self.LoginError(err_mess)
  
          self._suspended = False  # login worked
  
          return (session, req) if get_request else session
docs: Return a session for yesss.at.