old_contents: import os
  import sys
  
  if os.name == "posix":
      from posix_path \
          import \
              relpath
      rename = os.rename
  elif os.name == "nt":
      from nt_path \
          import \
              relpath
      from rename import rename
  else:
      raise ImportError("relpath implementation for os %s not included" \
                        % os.name)
  
  try:
      from subprocess \
          import \
              check_call, CalledProcessError
  except ImportError:
      from bento.compat._subprocess \
          import \
              check_call, CalledProcessError
  
  if sys.version_info < (2, 5, 0):
      from bento.compat._zipfile \
          import \
              ZipFile, ZIP_DEFLATED
  else:
      from zipfile \
          import \
              ZipFile, ZIP_DEFLATED
  
new_contents: import os
  import sys
  
  if os.name == "posix":
      from posix_path \
          import \
              relpath
      rename = os.rename
  elif os.name == "nt":
      from nt_path \
          import \
              relpath
      from rename import rename
  else:
      raise ImportError("relpath implementation for os %s not included" \
                        % os.name)
  
  try:
      from subprocess \
          import \
              check_call, CalledProcessError
  except ImportError:
      from bento.compat._subprocess \
          import \
              check_call, CalledProcessError
  
  if sys.version_info < (2, 6, 0):
      # zipfile for python < 2.6 has some issues with filename encoding, use or
      # own copy
      from bento.compat._zipfile \
          import \
              ZipFile, ZIP_DEFLATED
  else:
      from zipfile \
          import \
              ZipFile, ZIP_DEFLATED
  
subject: use our compat module for zip for python 2.5 as well.