code: def test_to_4D_image():
      for shape in (2, 4), (2, 4, 1), (1, 2, 4, 1):
          exp = tf.ones(shape=(1, 2, 4, 1))
          res = img_utils.to_4D_image(tf.ones(shape=shape))
          # static shape:
          assert exp.get_shape() == res.get_shape()
          np.testing.assert_equal(exp.numpy(), res.numpy())
  
file_path: addons/tensorflow_addons/image/tests/utils_test.py
imports: import pytest
  import numpy
  import tensorflow
  from tensorflow_addons.image import utils
label_desc: Use image node_id 4 for calling a global function with example usage: test_to_4D_image() without return types