code: def test_getitem(self):
      num = len(self.images)
      for i in range(-num, num):
          assert isinstance(self.images[i], np.ndarray)
      assert_allclose(self.images[0], self.images[-num])
  
      def return_img(n):
          return self.images[n]
  
      with testing.raises(IndexError):
          return_img(num)
      with testing.raises(IndexError):
          return_img(-num - 1)
  
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 3 for calling the TestImageCollection obj's underlying member method code with example usage: obj.test_getitem() and returns: self