code: def get_current_losses(self):
      return self.losses[self.iter]
  
imports: import unittest
  import torch
  import numpy
  import os
  import random
  import sys
  from torch_geometric.data import Data
  from torch_points3d.utils.geometry import rodrigues
  from torch_points3d.metrics.registration_tracker import FragmentRegistrationTracker
label_desc: Use image node_id 4 for calling the MockModel obj's underlying member method code with example usage: obj.get_current_losses() and returns: self