def METHOD_NAME(self):
    start_train_json = {
        "groupid": "38",
        "clientLearningRate": 0.001,
        "partitionMethod": "homo",
        "starttime": 1646068794775,
        "trainBatchSize": 64,
        "edgeids": [22, 126, 27],
        "token": "eyJhbGciOiJIUzI1NiJ9.eyJpZCI6NjAsImFjY291bnQiOiJhbGV4LmxpYW5nIiwibG9naW5UaW1lIjoiMTY0NjA2NTY5MDAwNSIsImV4cCI6MH0.0OTXuMTfxqf2duhkBG1CQDj1UVgconnoSH0PASAEzM4",
        "modelName": "lenet_mnist",
        "urls": [
            "https://fedmls3.s3.amazonaws.com/025c28be-b464-457a-ab17-851ae60767a9"
        ],
        "clientOptimizer": "adam",
        "userids": ["60"],
        "clientNumPerRound": 3,
        "name": "1646068810",
        "commRound": 3,
        "localEpoch": 1,
        "runId": 189,
        "id": 169,
        "projectid": "56",
        "dataset": "mnist",
        "communicationBackend": "MQTT_S3",
        "timestamp": "1646068794778",
    }
    self.communicator.send_message(
        "flserver_agent/27/start_train", json.dumps(start_train_json)
    )