code: def test_affine(self):
      test_img = nib.Nifti1Image(np.zeros((1, 2, 3)), np.eye(4) * 20.0)
      test_img = correct_nifti_header_if_necessary(test_img)
      np.testing.assert_allclose(
          test_img.affine,
          np.array(
              [
                  [20.0, 0.0, 0.0, 0.0],
                  [0.0, 20.0, 0.0, 0.0],
                  [0.0, 0.0, 20.0, 0.0],
                  [0.0, 0.0, 0.0, 20.0],
              ]
          ),
      )
  
file_path: MONAI/tests/test_header_correct.py
imports: from __future__ import annotations
  import unittest
  import nibabel
  import numpy
  from monai.data import correct_nifti_header_if_necessary
label_desc: Use image node_id 2 for calling the TestCorrection obj's underlying member method code with example usage: obj.test_affine() without return types