code: def test_propagation_hooks_ctx(self):
      def propagator(images, augmenter, parents, default):
          if ia.is_np_array(images):
              return False
          else:
              return True
  
      hooks = ia.HooksImages(propagator=propagator)
  
      batch = _BatchInAugmentation(
          images=np.zeros((3, 3, 4, 1), dtype=np.uint8),
          keypoints=[
              ia.KeypointsOnImage([ia.Keypoint(0, 0)], shape=(3, 4, 1)),
              ia.KeypointsOnImage([ia.Keypoint(1, 1)], shape=(3, 4, 1)),
              ia.KeypointsOnImage([ia.Keypoint(2, 2)], shape=(3, 4, 1)),
          ],
      )
  
      with batch.propagation_hooks_ctx(
          iaa.Identity(), hooks, []
      ) as batch_prop:
          assert batch_prop.images is None
          assert batch_prop.keypoints is not None
          assert len(batch_prop.keypoints) == 3
  
          batch_prop.keypoints[0].keypoints[0].x = 10
  
      assert batch.images is not None
      assert batch.keypoints is not None
      assert batch.keypoints[0].keypoints[0].x == 10
  
imports: from __future__ import print_function, division, absolute_import
  import warnings
  import sys
  import numpy
  import imgaug
  import imgaug.augmenters
  from imgaug.testutils import reseed
  from imgaug.augmentables.batches import _BatchInAugmentation
label_desc: Use image node_id 19 for calling the Test_BatchInAugmentation obj's underlying member method code with example usage: obj.test_propagation_hooks_ctx() and returns: False, True