code: def test_functional_threshold(self):
      threshold = -0.5
      actual = bin_acc(
          self.predictions, self.targets, threshold=threshold
      )
      label_predictions = (self.predictions > threshold).float()
      self.assertEqual((), actual.shape)
      np.testing.assert_almost_equal(
          (label_predictions == self.targets).float().mean() * 100,
          actual,
      )
  
imports: from unittest import TestCase, skipIf
  import numpy
  import torch
  from poutyne import Accuracy, BinaryAccuracy, TopKAccuracy, acc, bin_acc, topk
label_desc: Use image node_id 12 for calling the BinaryAccuracyTest obj's underlying member method code with example usage: obj.test_functional_threshold() without return types