code: def test_environment_assumes_empty_extra(self):
      assert Marker('extra == "im_valid"').evaluate() is False
  
imports: import collections
  import itertools
  import os
  import platform
  import sys
  from typing import cast
  import pytest
  from packaging._parser import Node
  from packaging.markers import InvalidMarker, Marker, UndefinedComparison, default_environment, format_full_version
label_desc: Use image node_id 6 for calling the TestMarker obj's underlying member method code with example usage: obj.test_environment_assumes_empty_extra() without return types