new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  """
  Created by René Meusel
  This file is part of the CernVM File System auxiliary tools.
  """
  
  import abc
  import os
  import tempfile
  import unittest
  
  class FileSandbox(unittest.TestCase):
      """ Wraps the creation and automatic removal of temporary files """
  
      __metaclass__   = abc.ABCMeta
  
      def __init__(self, *args, **kwargs):
          super(FileSandbox, self).__init__(*args, **kwargs)
          self.temporary_files = []
  
      def __del__(self):
          for f in self.temporary_files:
              os.unlink(f)
          # del self.temporary_files[:]
  
      @abc.abstractmethod
      def temporary_prefix(self):
          """ defines a unique temporary file prefix """
          return "file_sandbox"
  
  
      def write_to_temporary(self, string_buffer):
          """ stores the provided content into a /tmp path that is returned """
          filename = None
          with tempfile.NamedTemporaryFile(mode='w+b',
                                           prefix=self.temporary_prefix(),
                                           dir='/tmp',
                                           delete=False) as f:
              filename = f.name
              f.write(string_buffer)
              self.temporary_files.append(filename)
          return filename
  
subject: add missing file 'file_sandbox.py'