code: def new_wins(self, orig_criteria, orig_idx, new_criteria, new_idx):
      
      raise NotImplementedError(str(type(self))
                                + " needs to implement new_wins.")
docs: Returns a bool indicating whether a new adversarial example is better
      than the pre-existing one for the same clean example.
      :param orig_criteria: dict mapping names of criteria to their value
        for each example in the whole dataset
      :param orig_idx: The position of the pre-existing example within the
        whole dataset.
      :param new_criteria: dict, like orig_criteria, but with values only
        on the latest batch of adversarial examples
      :param new_idx: The position of the new adversarial example within
        the batch