code: def test_generator():
      # User iter_axis to return slices
      gen = iter_axis(gimg, axis=0)
      for img_slice in gen:
          assert img_slice.shape == (3, 2)
  
imports: import warnings
  from itertools import chain
  import nibabel
  import numpy
  import pytest
  from numpy.testing import assert_almost_equal, assert_array_almost_equal, assert_array_equal
  from ...api import data_generator, parcels, write_data
  from ...reference.coordinate_map import AffineTransform, AxisError
  from ...reference.coordinate_system import CoordinateSystem
  from ..None import image
  from ..image import Image, is_image, iter_axis, rollimg
label_desc: Use image node_id 9 for calling a global function with example usage: test_generator() without return types