def test_save(self):
     """
     System test for persisting changes into a file.
     """
     config_content = (
         u'[another_muță]\n'
         u'another_muță_option: another_muță_value\n\n')
     test_filesystem = manufacture.fs
     test_segments = None
     try:
         test_segments = test_filesystem.createFileInTemp(
             content=config_content)
         config_path = test_filesystem.getRealPathFromSegments(
             test_segments)
         with test_filesystem._impersonateUser():
             config = FileConfigurationProxy(
                 configuration_path=config_path)
             config.load()
             self.assertEqual(
                 u'another_muță_value',
                 config.getString(
                     u'another_muță',
                     u'another_muță_option'))
             config.setString(
                     u'another_muță',
                     u'another_muță_option',
                     u'muță_value',
                     )
             config.save()
             config = FileConfigurationProxy(
                 configuration_path=config_path)
             config.load()
             self.assertEqual(
                 u'muță_value',
                 config.getString(
                     u'another_muță',
                     u'another_muță_option'))
     finally:
         if test_segments:
             test_filesystem.deleteFile(test_segments, ignore_errors=True)