def METHOD_NAME(cls, call_context: _AwsSdkCallContext):
    payload_str = call_context.params.get("Payload")
    if payload_str is None:
        return
    # TODO: reconsider propagation via payload as it manipulates input of the called lambda function
    try:
        payload = json.loads(payload_str)
        headers = payload.get("headers", {})
        inject(headers)
        payload["headers"] = headers
        call_context.params["Payload"] = json.dumps(payload)
    except ValueError:
        pass