old_contents: from django.test import TestCase
  from django.contrib.auth import get_user_model
  
  
  class TestPost(TestCase):
  
      def setUp(self):
          self.test_username = "test_user"
          self.test_userpassword = "test_password"
  
          user = self.user = get_user_model().objects.create_user(
              username=self.test_username,
              password=self.test_userpassword,
          )
  
          self.assertEqual(
              user.username,
              self.test_username
          )
  
          # Create Post
          self.post_video_id = "lcmAdIdSA5k"
  
          self.post = self.user.post_set.create(
              video_id=self.post_video_id,
              title="test_title",
          )
  
      def test_post_model_should_have_youtube_origin_url(self):
          """
          Post 모델은 가지고 있는 video_id를 이용해서
          youtube 원본영상의 링크를 생성할 수 있어야 한다.
          """
          self.assertEqual(
              self.post.get_youtube_original_url(),
              "https://www.youtube.com/watch?v={post_video_id}".format(
                  post_video_id=self.post_video_id,
              )
          )
  
new_contents: from django.test import TestCase
  from django.contrib.auth import get_user_model
  
  
  class TestPost(TestCase):
  
      def setUp(self):
          self.test_username = "test_user"
          self.test_userpassword = "test_password"
  
          user = self.user = get_user_model().objects.create_user(
              username=self.test_username,
              password=self.test_userpassword,
          )
  
          self.assertEqual(
              user.username,
              self.test_username
          )
  
          # Create Post
          self.post_video_id = "lcmAdIdSA5k"
  
          self.post = self.user.post_set.create(
              video_id=self.post_video_id,
              title="test_title",
          )
  
      def test_post_model_should_have_youtube_origin_url(self):
          """
          Post 모델은 가지고 있는 video_id를 이용해서
          youtube 원본영상의 링크를 생성할 수 있어야 한다.
          """
          self.assertEqual(
              self.post.youtube_original_url,
              "https://www.youtube.com/watch?v={post_video_id}".format(
                  post_video_id=self.post_video_id,
              )
          )
  
subject: refactor Posts Test