def __init__()

in train/model.py [0:0]


    def __init__(self,
                 net,
                 criterion,
                 model_prefix='',
                 step_callback=None,
                 step_callback_freq=20,
                 epoch_callback=None,
                 save_checkpoint_freq=1,
                 opt_batch_size=None,
                 **kwargs):

        # load parameters
        super(model, self).__init__(net, criterion=criterion,
                                         model_prefix=model_prefix,
                                         **kwargs)

        # load optional arguments
        # - callbacks
        self.callback_kwargs = {'lr': None,
                                'epoch': None,
                                'batch': None,
                                'batch_elapse': None,
                                'update_elapse': None,
                                'epoch_elapse': None,
                                'namevals': None,
                                'optimizer_dict': None,}

        if not step_callback:
            step_callback = callback.CallbackList(callback.SpeedMonitor(),
                                                  callback.MetricPrinter())
        if not epoch_callback:
            epoch_callback = (lambda **kwargs: None)

        self.step_callback = step_callback
        self.step_callback_freq = step_callback_freq
        self.epoch_callback = epoch_callback
        self.save_checkpoint_freq = save_checkpoint_freq
        self.batch_size=opt_batch_size