def create_model(model_folder, model_type, topology, override):
    """
    Create a model if it doesn't exist already.

    Parameters
    ----------
    model_folder :
        The path to the folder where the model is described with an `info.yml`
    model_type :
        MLP
    topology :
        Something like 160:500:369 - that means the first layer has 160
        neurons, the second layer has 500 neurons and the last layer has 369
        neurons.
    override : boolean
        If a model exists, override it.
    """
    latest_model = utils.get_latest_in_folder(model_folder, ".json")
    if (latest_model == "") or override:
        logging.info("Create a base model...")
        model_src = os.path.join(model_folder, "model-0.json")
        command = "%s make %s %s > %s" % (utils.get_nntoolkit(),
                                          model_type,
                                          topology,
                                          model_src)
        logging.info(command)
        os.system(command)
    else:
        logging.info("Model file already existed.")
Create a model if it doesn't exist already.

    Parameters
    ----------
    model_folder :
        The path to the folder where the model is described with an `info.yml`
    model_type :
        MLP
    topology :
        Something like 160:500:369 - that means the first layer has 160
        neurons, the second layer has 500 neurons and the last layer has 369
        neurons.
    override : boolean
        If a model exists, override it.