docs: def is_down(queue, host=None):
      '''Returns True if queue is down, False if queue is up'''
      down_path = fsq_path.down(queue, host=host)
      _queue_ok(os.path.dirname(down_path))
      # use stat instead of os.path.exists because non-ENOENT errors are a
      # configuration issue, and should raise exeptions (e.g. if you can't
      # access due to permissions, we want to raise EPERM, not return False)
      try:
          os.stat(down_path)
      except (OSError, IOError, ), e:
          if e.errno == errno.ENOENT:
              return False
          raise FSQConfigError(e.errno, wrap_io_os_err(e))
      return True