code: def _inf_tensor(self, *shape):
      return 1.0 / torch.zeros(*shape, device=self.model.device)
  
imports: import itertools
  import unittest
  from contextlib import contextmanager
  from copy import deepcopy
  import torch
  from detectron2.structures import BitMasks, Boxes, ImageList, Instances
  from detectron2.utils.events import EventStorage
  from detectron2.utils.testing import get_model_no_weights
label_desc: Use image node_id 4 for calling the InstanceModelE2ETest obj's underlying member method code with example usage: obj._inf_tensor() and returns: unknown