docs: def thin_sum(cachedir, form='sha1'):
      '''
      Return the checksum of the current thin tarball
      '''
      thintar = gen_thin(cachedir)
      code_checksum_path = os.path.join(cachedir, 'thin', 'code-checksum')
      if os.path.isfile(code_checksum_path):
          with salt.utils.files.fopen(code_checksum_path, 'r') as fh:
              code_checksum = "'{0}'".format(fh.read().strip())
      else:
          code_checksum = "'0'"
  
      return code_checksum, salt.utils.hashutils.get_hash(thintar, form)