code: def get_labels(self):
      return self.labels[self.iter]
  
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 3 for calling the MockModel obj's underlying member method code with example usage: obj.get_labels() and returns: self