def METHOD_NAME(self):
    email, password = self._get_login_info()
    if email is None:
        return
    result = self._download_json(
        self._API_BASE_URL + 'login', None, data=urlencode_postdata({
            'email': email,
            'password': password,
        }))
    self._handle_errors(result)
    self._auth_token = result['message']['auth_token']