code: def test_custom_load_func_w_kwarg(self):
      load_pattern = fetch("data/no_time_for_that_tiny.gif")
  
      def load_fn(f, step):
          vid = iio3.imiter(f)
          return list(itertools.islice(vid, None, None, step))
  
      ic = ImageCollection(load_pattern, load_func=load_fn, step=3)
      # Each file should map to one image (array).
      assert len(ic) == 1
      # GIF file has 24 frames, so 24 / 3 equals 8.
      assert len(ic[0]) == 8
  
imports: import os
  import itertools
  import numpy
  import imageio.v3
  from skimage import data_dir
  from skimage.io.collection import ImageCollection, MultiImage, alphanumeric_key
  from skimage.io import reset_plugins
  from skimage._shared import testing
  from skimage._shared.testing import assert_equal, assert_allclose, fetch
  import pytest
label_desc: Use image node_id 7 for calling the TestImageCollection obj's underlying member method code with example usage: obj.test_custom_load_func_w_kwarg() and returns: list