code: def is_3dlist(x):
      """check x is 3d-list([[[1], []]]) or 2d empty list([[], []]) or 1d empty
      list([]).
  
      Notice:
          The reason that it contains 1d or 2d empty list is because
          some arguments from gt annotation file or model prediction
          may be empty, but usually, it should be 3d-list.
      """
      if not isinstance(x, list):
          return False
      if len(x) == 0:
          return True
      for sub_x in x:
          if not is_2dlist(sub_x):
              return False
  
      return True
  
label_desc: Use image node_id 1 for calling a global function with example usage: is_3dlist(x) and returns: True, False, True, False