code: def test_source_date_epoch(self):
      py_compile.compile(self.source_path, self.pyc_path)
      self.assertTrue(os.path.exists(self.pyc_path))
      self.assertFalse(os.path.exists(self.cache_path))
      with open(self.pyc_path, "rb") as fp:
          flags = importlib._bootstrap_external._classify_pyc(
              fp.read(), "test", {}
          )
      if os.environ.get("SOURCE_DATE_EPOCH"):
          expected_flags = 0b11
      else:
          expected_flags = 0b00
  
      self.assertEqual(flags, expected_flags)
  
imports: import functools
  import importlib.util
  import os
  import py_compile
  import shutil
  import stat
  import subprocess
  import sys
  import tempfile
  import unittest
  from test import support
  from test.support import os_helper, script_helper
label_desc: Use image node_id 11 for calling the PyCompileTestsBase obj's underlying member method code with example usage: obj.test_source_date_epoch() without return types