code: def test_classtosegments(self):
      dataset = ForwardShapenetDataset(self.config)
      self.assertEqual(
          dataset.class_to_segments,
          {"Airplane": [0, 1, 2, 3], "Cap": [6, 7]},
      )
  
imports: import unittest
  import os
  import sys
  import torch
  from omegaconf.dictconfig import DictConfig
  import numpy.testing
  import numpy
  import copy
  from test.mock_models import MockModel
  from torch_points3d.datasets.segmentation.forward.shapenet import _ForwardShapenet, ForwardShapenetDataset
label_desc: Use image node_id 9 for calling the TestForwardData obj's underlying member method code with example usage: obj.test_classtosegments() without return types