grabs the configuration, and makes the call to Authentise to create the session

def __create_session(username=None, password=None):
        """grabs the configuration, and makes the call to Authentise to create the session"""
        config = Config()

        if not username or not password:
            username = config.username
            password = config.password

        payload = {
            "username": username,
            "password": password,
        }

        session_resp = requests.post("https://users.{}/sessions/".format(config.host), json=payload)
        if session_resp.status_code == 403:
            raise errors.ResourceError("bad user credentials")

        return session_resp.cookies["session"]