old_contents: import unittest
  
  class TestZencoder(unittest.TestCase):
      def setUp(self):
          """ Initialize Zencoder for testing """
          pass
  
  if __name__ == "__main__":
      unittest.main()
  
  
new_contents: import unittest
  from zencoder import Zencoder
  
  class TestZencoder(unittest.TestCase):
      def setUp(self):
          """ Initialize Zencoder for testing """
          pass
  
      def test_api_key(self):
          """ initialize zencoder object and test api key """
          api_key = 'abcd123'
          zc = Zencoder(api_key=api_key)
          self.assertEquals(zc.api_key, api_key)
  
  if __name__ == "__main__":
      unittest.main()
  
  
subject: add test for setting the api_key with the default arg