docs: def find_window_id(pattern, method='mru', error='raise'):
          """
          xprop -id 0x00a00007 | grep "WM_CLASS(STRING)"
          """
          import utool as ut
          winid_candidates = XCtrl.findall_window_ids(pattern)
          if len(winid_candidates) == 0:
              if error == 'raise':
                  available_windows = ut.cmd2('wmctrl -l')['out']
                  msg = 'No window matches pattern=%r' % (pattern,)
                  msg += '\navailable windows are:\n%s' % (available_windows,)
                  print(msg)
                  raise Exception(msg)
              win_id = None
          elif len(winid_candidates) == 1:
              win_id = winid_candidates[0]
          else:
              # print('Multiple (%d) windows matches pattern=%r' % (
              #     len(winid_list), pattern,))
              # Find most recently used window with the focus name.
              win_id = XCtrl.sort_window_ids(winid_candidates, method)[0]
          return win_id