old_contents: import random
  import string
  import unittest
  
  from tweepy.utils import *
  
  
  def mock_tweet():
      """Generate some random tweet text."""
      count = random.randint(70, 140)
      return ''.join([random.choice(string.ascii_letters) for _ in range(count)])
  
  
  class TweepyUtilsTests(unittest.TestCase):
  
      def testlist_to_csv(self):
          self.assertEqual("1,2,3", list_to_csv([1,2,3]))
          self.assertEqual("bird,tweet,nest,egg",
                           list_to_csv(["bird", "tweet", "nest", "egg"]))
  
new_contents: import unittest
  
  from tweepy.utils import *
  
  
  class TweepyUtilsTests(unittest.TestCase):
  
      def testlist_to_csv(self):
          self.assertEqual("1,2,3", list_to_csv([1,2,3]))
          self.assertEqual("bird,tweet,nest,egg",
                           list_to_csv(["bird", "tweet", "nest", "egg"]))
  
subject: Remove mock_tweet