code: def _clean_prior(self):
          
  
          if self._loaded:
              try:
                  pid_file = daemon.get_daemon_pidfile(self)
  
                  # check if it exists so we don't raise
                  if os.path.isfile(pid_file):
                      # read pid from file
                      pid = int(common.readfile(pid_file))
  
                      # check if pid file is stale
                      if pid and not daemon.pid_exists(pid):
                          common.safe_remove_file(pid_file)
                          raise ValueError
  
              except (ValueError, TypeError):
                  self._clean()
                  return True
  
          return False
docs: Cleans up from a previous task that didn't exit cleanly.
  
              Returns ``True`` if previous task was cleaned.