new_contents: #!/usr/bin/env python
  
  import unittest
  import sys
  
  from hn import HN, Story
  
  class TestStory(unittest.TestCase):
      
      def setUp(self):
          self.PY2 = sys.version_info[0] == 2
          if not PY2:
              self.text_type = [str]
          else:
              self.text_type = [unicode, str]
          self.story = Story('6115341') # https://news.ycombinator.com/item?id=6115341
      
      def tearDown(self):
          pass
      
      def test_story_repr(self):
          """
          Check string repr of the story.
          """
          self.assertEqual(self.story, '<Story: ID=6115341>')
      
      def test_story_data_types(self):
          """
          Test types of fields of a Story object
          """
          assert type(self.story.rank) == int
          assert type(self.story.self.story_id) == int
          assert type(self.story.title) in self.text_type
          assert type(self.story.link) in self.text_type
          assert type(self.story.domain) in self.text_type
          assert type(self.story.points) == int
          assert type(self.story.submitter) in self.text_type
          assert type(self.story.published_time) in self.text_type
          assert type(self.story.submitter_profile) in self.text_type
          assert type(self.story.num_comments) == int
          assert type(self.story.comments_link) in self.text_type
          assert type(self.story.is_self) == bool
subject: add some unit tests