code: def assert_img_equal_img_string(a, b_string):
      assert img_to_string(a) == img_string_normalize(b_string)
  
imports: from __future__ import annotations
  import pytest
  from PIL import Image, ImageMorph, _imagingmorph
  from .helper import assert_image_equal_tofile, hopper
label_desc: Use image node_id 4 for calling a global function with example usage: assert_img_equal_img_string(a, b_string) without return types