'Args:
pred_tensor_name(str): name of the 0/1 prediction tensor.
label_tensor_name(str): name of the 0/1 label tensor.'

def __init__(self, pred_tensor_name, label_tensor_name, prefix='val'):

    self.pred_tensor_name = pred_tensor_name
    self.label_tensor_name = label_tensor_name
    self.prefix = prefix
