def __init__(self, pred_tensor_name, label_tensor_name, prefix='val'):
        """
        Args:
            pred_tensor_name(str): name of the 0/1 prediction tensor.
            label_tensor_name(str): name of the 0/1 label tensor.
        """
        self.pred_tensor_name = pred_tensor_name
        self.label_tensor_name = label_tensor_name
        self.prefix = prefix

        Args:
            pred_tensor_name(str): name of the 0/1 prediction tensor.
            label_tensor_name(str): name of the 0/1 label tensor.
        
tensorpack/callbacks/inference.py