code: def _test_leak(self, core):
      start_mem = self._get_mem_usage()
      for cycle in range(self.iterations):
          core()
          mem = self._get_mem_usage() - start_mem
          msg = f"memory usage limit exceeded in iteration {cycle}"
          assert mem < self.mem_limit, msg
  
imports: import logging
  import os
  import shutil
  import sys
  import sysconfig
  import tempfile
  from io import BytesIO
  import pytest
  from packaging.version import parse
  from PIL import Image, ImageMath, features
label_desc: Use image node_id 2 for calling the PillowLeakTestCase obj's underlying member method code with example usage: obj._test_leak(core) without return types