code: def md5sum(fname):
      with open(fname, "rb") as fobj:
          return hashlib.md5(fobj.read()).hexdigest()
  
imports: import contextlib
  import hashlib
  import os
  import time
  import unittest
  from gzip import GzipFile
  from io import BytesIO, UnsupportedOperation
  from unittest import mock
  import pytest
  from packaging.version import Version
  from ..deprecator import ExpiredDeprecationError
  from ..openers import HAVE_INDEXED_GZIP, BZ2File, DeterministicGzipFile, ImageOpener, Opener
  from ..optpkg import optional_package
  from ..tmpdirs import InTemporaryDirectory
label_desc: Use image node_id 12 for calling a global function with example usage: md5sum(fname) and returns: hashlib