recipe definition and payload

These functions are missing the return statement.

def set_payload(self, payload):
    """
    Set the raw payload of this recipe
    :param str payload: the payload, as a string
    """
    self.data['payload'] = payload

def set_json_payload(self, payload):
    """
    Set the raw payload of this recipe
    :param dict payload: the payload, as a dict. The payload will be converted to a JSON string internally
    """
    self.data['payload'] = json.dumps(payload)

先定位 set_payload 和 set_json_payload 的 recipe 定義，接著檢查呼叫端如何使用這些方法，以及類似方法是否會回傳值。根據周圍 API client 的慣例確認預期的回傳行為，並為兩個 payload setter 新增涵蓋或驗證，之後再將該 issue 視為完成。