code: def test_iou(self):
      i1 = _Instance(
          classname=1, indices=np.array([1, 2, 3]), score=1, scan_id=0
      )
      i2 = _Instance(
          classname=1, indices=np.array([1, 2, 3]), score=1, scan_id=0
      )
      self.assertEqual(i1.iou(i2), 1)
  
      i2 = _Instance(
          classname=1, indices=np.array([1, 4]), score=1, scan_id=0
      )
      self.assertEqual(i1.iou(i2), 0.25)
  
imports: import os
  import sys
  import unittest
  import torch
  import numpy
  from torch_geometric.data import Data
  from torch_points3d.models.panoptic.structures import PanopticResults, PanopticLabels
  from torch_points3d.metrics.panoptic_tracker import _Instance, InstanceAPMeter, PanopticTracker
label_desc: Use image node_id 1 for calling the TestInstance obj's underlying member method code with example usage: obj.test_iou() without return types