old_contents: # coding: utf-8
  from __future__ import absolute_import
  from __future__ import unicode_literals
  
  import io
  import os
  import unittest
  import tempfile
  
  try:
      from unittest import mock
  except ImportError:
      import mock
  
  from fs.archive import _utils
  
  
  class TestUtils(unittest.TestCase):
  
      @unittest.skipUnless(os.name == 'posix', 'POSIX platform needed')
      def test_writable_path(self):
          self.assertFalse(_utils.writable_path('/'))
          self.assertFalse(_utils.writable_path('/root_location'))
          self.assertTrue(_utils.writable_path(__file__))
  
      def test_writable_stream(self):
          with tempfile.NamedTemporaryFile() as tmp:
              self.assertTrue(_utils.writable_stream(tmp))
              with open(tmp.name) as tmp2:
                  self.assertFalse(_utils.writable_stream(tmp2))
  
          buff = io.BytesIO()
          self.assertTrue(_utils.writable_stream(buff))
          buff = io.BufferedReader(buff)
          self.assertFalse(_utils.writable_stream(buff))
  
          buff = mock.MagicMock()
          buff.write = mock.MagicMock(side_effect=IOError("not writable"))
          self.assertFalse(_utils.writable_stream(buff))
  
      def test_import_from_names(self):
          imp = _utils.import_from_names
          self.assertIs(imp('os'), os)
          self.assertIs(imp('akjhkjhsk', 'os'), os)
          self.assertIs(imp('akeskjhk'), None)
  
new_contents: # coding: utf-8
  from __future__ import absolute_import
  from __future__ import unicode_literals
  
  import io
  import os
  import unittest
  import tempfile
  
  try:
      from unittest import mock
  except ImportError:
      import mock
  
  from fs.archive import _utils
  
  
  class TestUtils(unittest.TestCase):
  
      @unittest.skipUnless(os.name == 'posix', 'POSIX platform needed')
      def test_writable_path(self):
          self.assertFalse(_utils.writable_path('/'))
          self.assertFalse(_utils.writable_path('/root_location'))
          self.assertTrue(_utils.writable_path(__file__))
  
      def test_writable_stream(self):
          with tempfile.NamedTemporaryFile(mode='wb+') as tmp:
              self.assertTrue(_utils.writable_stream(tmp))
              with open(tmp.name, 'rb') as tmp2:
                  self.assertFalse(_utils.writable_stream(tmp2))
  
          buff = io.BytesIO()
          self.assertTrue(_utils.writable_stream(buff))
          buff = io.BufferedReader(buff)
          self.assertFalse(_utils.writable_stream(buff))
  
          buff = mock.MagicMock()
          buff.write = mock.MagicMock(side_effect=IOError("not writable"))
          self.assertFalse(_utils.writable_stream(buff))
  
      def test_import_from_names(self):
          imp = _utils.import_from_names
          self.assertIs(imp('os'), os)
          self.assertIs(imp('akjhkjhsk', 'os'), os)
          self.assertIs(imp('akeskjhk'), None)
  
subject: Fix test_writable_stream failing in Python 3.3 and 3.4