code: def test_images(self):
      # Assumes all possible images support int16
      # See https://github.com/nipy/nibabel/issues/58
      arr = np.arange(24, dtype=np.int16).reshape((2, 3, 4))
      img = self.image_class(arr, None)
      assert (img.get_fdata() == arr).all()
      assert img.affine is None
  
imports: from io import BytesIO
  import numpy
  import pytest
  from numpy.testing import assert_array_almost_equal
  from ..None import load
  from ..imageclasses import spatial_axes_first
  from ..spatialimages import HeaderDataError, SpatialHeader, SpatialImage
  from ..testing import bytesio_round_trip, expires, memmap_after_ufunc
  from ..tmpdirs import InTemporaryDirectory
label_desc: Use image node_id 3 for calling the TestSpatialImage obj's underlying member method code with example usage: obj.test_images() without return types