code: def updated(bank, key, cachedir):
      '''
      Return the epoch of the mtime for this cache file
      '''
      key_file = os.path.join(cachedir, os.path.normpath(bank), '{0}.p'.format(key))
      if not os.path.isfile(key_file):
          log.warning('Cache file "%s" does not exist', key_file)
          return None
      try:
          return int(os.path.getmtime(key_file))
      except IOError as exc:
          raise SaltCacheError(
              'There was an error reading the mtime for "{0}": {1}'.format(
                  key_file, exc
              )
          f updated(bank, key, cachedir):
      '''
      Return the epoch of the mtime for this cache file
      '''
      key_file = os.path.join(cachedir, os.path.normpath(bank), '{0}.p'.format(key))
      if not os.path.isfile(key_file):
          log.warning('Cache file "%s" does not exist', key_file)
          return None
      try:
          return int(os.path.getmtime(key_file))
      except IOError as exc:
          raise SaltCacheError(
              'There was an error reading the mtime for "{0}": {1}'.format(
                  key_file, exc
              )
          )
docs: Return the epoch of the mtime for this cache file