code: def test_reducing_gap_values():
      im = hopper()
      im.thumbnail((18, 18), Image.BICUBIC)
  
      ref = hopper()
      ref.thumbnail((18, 18), Image.BICUBIC, reducing_gap=2.0)
      # reducing_gap=2.0 should be the default
      assert_image_equal(ref, im)
  
      ref = hopper()
      ref.thumbnail((18, 18), Image.BICUBIC, reducing_gap=None)
      with pytest.raises(AssertionError):
          assert_image_equal(ref, im)
  
      assert_image_similar(ref, im, 3.5)
  
file_path: pillow-simd/Tests/test_image_thumbnail.py
imports: import pytest
  from PIL import Image
  from .helper import assert_image_equal, assert_image_similar, fromstring, hopper, tostring
label_desc: Use image node_id 7 for calling a global function with example usage: test_reducing_gap_values() without return types