code: def _get_library_file(self):
      return os.path.join(
          self._root_dir,
          "lib",
          self._platform,
          self._arch,
          "libpv_porcupine." + get_lib_ext(self._platform),
      )
  
file_path: porcupine/demo/c/test/test_porcupine_c.py
imports: import os.path
  import subprocess
  import sys
  import unittest
  from parameterized import parameterized
  from test_util import *
label_desc: Use image node_id 2 for calling the PorcupineCTestCase obj's underlying member method code with example usage: obj._get_library_file() and returns: os