code: def test_path(self):
      # no suffix
      result = search_files(DATA_PATH)
      self.assertEqual(result, sorted(FILE_LIST))
      # single suffix
      result = search_files(DATA_PATH, suffix="txt")
      file_list = [
          pj(DATA_PATH, "commented_txt"),
          pj(DATA_PATH, "events.txt"),
      ]
      self.assertEqual(result, sorted(file_list))
      # another suffix
      result = search_files(DATA_PATH, suffix=".txt")
      file_list = [pj(DATA_PATH, "events.txt")]
      self.assertEqual(result, sorted(file_list))
      # suffix list
      result = search_files(DATA_PATH, suffix=[".txt", "txt"])
      file_list = [
          pj(DATA_PATH, "commented_txt"),
          pj(DATA_PATH, "events.txt"),
      ]
      self.assertEqual(result, sorted(file_list))
  
imports: from __future__ import absolute_import, division, print_function
  import unittest
  from os.path import join
  from madmom.utils import *
  from .None import ACTIVATIONS_PATH, ANNOTATIONS_PATH, AUDIO_PATH, DATA_PATH, DETECTIONS_PATH
  from .test_evaluation_notes import ANNOTATIONS
label_desc: Use image node_id 2 for calling the TestSearchFilesFunction obj's underlying member method code with example usage: obj.test_path() without return types