docs: def sorted_window_ids(order='mru'):
          """
          Returns window ids orderd by criteria
          default is mru (most recently used)
  
          CommandLine:
              xprop -root | grep "^_NET_CLIENT_LIST_STACKING" | tr "," " "
              python -m utool.util_ubuntu XCtrl.sorted_window_ids
          """
          import utool as ut
          if order in ['mru', 'lru']:
              cmdkw = dict(verbose=False, quiet=True, silence=True)
              winid_order_str = ut.cmd(
                  'xprop -root | grep "^_NET_CLIENT_LIST_STACKING"', **cmdkw)[0]
              winid_order = winid_order_str.split('#')[1].strip().split(', ')[::-1]
              winid_order = [int(h, 16) for h in winid_order]
              if order == 'lru':
                  winid_order = winid_order[::-1]
          else:
              raise NotImplementedError(order)
          return winid_order