old_contents: """Tests for errors.py"""
  
  import unittest
  import unittest.mock
  
  import aiohttp
  
  
  class TestErrors(unittest.TestCase):
  
      def test_bad_status_line(self):
          err = aiohttp.BadStatusLine(b'')
          self.assertEqual(str(err), "b''")
  
          err = aiohttp.BadStatusLine('Test')
          self.assertEqual(str(err), 'Test')
  
new_contents: """Tests for errors.py"""
  
  import aiohttp
  
  
  def test_bad_status_line1():
      err = aiohttp.BadStatusLine(b'')
      assert str(err) == "b''"
  
  
  def test_bad_status_line2():
      err = aiohttp.BadStatusLine('Test')
      assert str(err) == 'Test'
  
subject: Convert test_errors to pytest style