code: def test_dry_run(self):
      flow = naf.Sequential([naf.Sequential()])
      results = flow.augment([])
      self.assertEqual(0, len(results))
  
imports: import unittest
  import os
  import numpy
  from dotenv import load_dotenv
  import nlpaug.augmenter.char
  import nlpaug.augmenter.word
  import nlpaug.augmenter.audio
  import nlpaug.augmenter.spectrogram
  import nlpaug.flow
  from nlpaug.util.audio.loader import AudioLoader
  from nlpaug.util import Action
label_desc: Use image node_id 2 for calling the TestFlow obj's underlying member method code with example usage: obj.test_dry_run() without return types