old_contents: import unittest
  import logging
  logging.getLogger().setLevel(logging.DEBUG)
  
  from .. import common
  import os
  
  class TestCase(unittest.TestCase):
      def test_backup1(self):
          path = common.backup('common.pz', copy=False)
          self.assertEqual(path, '')
  
      def test_backup2(self):
          path = common.backup('test_common.py', copy=False)
          self.assertEqual(os.path.dirname(path), os.getcwd())
          self.assertEqual(os.path.basename(path), 'test_common.py.1')
new_contents: import unittest
  import logging
  logging.getLogger().setLevel(logging.DEBUG)
  
  from .. import common
  import os
  
  class TestCase(unittest.TestCase):
      def test_backup1(self):
          path = common.backup('common.pz', copy=False)
          self.assertEqual(path, '')
  
      def test_backup2(self):
          path = common.backup(os.path.join(os.path.dirname(__file__), 'test_common.py'), copy=False)
          self.assertEqual(os.path.dirname(path), os.path.dirname(__file__))
          self.assertEqual(os.path.basename(path), 'test_common.py.1')
subject: Fix test.