code: def test_get_affine():
      shape = (1, 2, 3, 4)
      data = np.random.randint(0, 10, shape)
      affine = np.eye(4)
      ref_im = VolumeImg(data, affine, "mine")
      np.testing.assert_equal(ref_im.affine, ref_im.get_affine())
  
imports: import copy
  import numpy
  import pytest
  from numpy.testing import assert_almost_equal, assert_array_equal
  from ...transforms.affine_transform import AffineTransform
  from ...transforms.affine_utils import from_matrix_vector
  from ...transforms.transform import Transform
  from ..volume_img import CompositionError, VolumeImg
label_desc: Use image node_id 12 for calling a global function with example usage: test_get_affine() without return types