code: def eval_advs(self, x, y, preds_adv, X_test, Y_test, att_type):
      
      end = (len(X_test) // self.batch_size) * self.batch_size
  
      if self.hparams.fast_tests:
        end = 10*self.batch_size
  
      acc = model_eval(self.sess, x, y, preds_adv, X_test[:end],
                       Y_test[:end], args=self.eval_params)
      self.log_value('test_accuracy_%s' % att_type, acc,
                     'Test accuracy on adversarial examples')
      return acc
docs: Evaluate the accuracy of the model on adversarial examples
  
      :param x: symbolic input to model.
      :param y: symbolic variable for the label.
      :param preds_adv: symbolic variable for the prediction on an
                        adversarial example.
      :param X_test: NumPy array of test set inputs.
      :param Y_test: NumPy array of test set labels.
      :param att_type: name of the attack.