code: def test_split_merge(mode):
      expected = Image.merge(mode, hopper(mode).split())
      assert_image_equal(hopper(mode), expected)
  
imports: from __future__ import annotations
  import pytest
  from PIL import Image, features
  from .helper import assert_image_equal, hopper
label_desc: Use image node_id 2 for calling a global function with example usage: test_split_merge(mode) without return types