code: def test_process_message_stack(self):
      relative_path = "../.."
  
      p = Porcupine(
          access_key=sys.argv[1],
          library_path=pv_library_path(relative_path),
          model_path=get_model_path_by_language(relative_path, "en"),
          keyword_paths=get_keyword_paths_by_language(
              relative_path, "en", ["porcupine"]
          ),
          sensitivities=[0.5],
      )
      test_pcm = [0] * p.frame_length
  
      address = p._handle
      p._handle = None
  
      try:
          res = p.process(test_pcm)
          self.assertEqual(res, 100)
      except PorcupineError as e:
          self.assertGreater(len(e.message_stack), 0)
          self.assertLess(len(e.message_stack), 8)
  
      p._handle = address
  
file_path: porcupine/binding/python/test_porcupine.py
imports: import sys
  import unittest
  from parameterized import parameterized
  from _porcupine import Porcupine, PorcupineError
  from test_util import *
label_desc: Use image node_id 6 for calling the PorcupineTestCase obj's underlying member method code with example usage: obj.test_process_message_stack() without return types