code: def test_signedness(self):
      # see https://github.com/python-pillow/Pillow/issues/452
      # pixelaccess is using signed int* instead of uint*
      for mode in ("I;16", "I;16B"):
          self.check(mode, 2**15 - 1)
          self.check(mode, 2**15)
          self.check(mode, 2**15 + 1)
          self.check(mode, 2**16 - 1)
  
imports: import ctypes
  import os
  import subprocess
  import sys
  import sysconfig
  import pytest
  from setuptools.command.build_ext import new_compiler
  from PIL import Image
  from .helper import assert_image_equal, hopper, is_win32, on_ci
label_desc: Use image node_id 4 for calling the TestImageGetPixel obj's underlying member method code with example usage: obj.test_signedness() without return types