code: def test_data(self):
      return Data(pos=self.pos, y=self.test_label)
  
imports: import unittest
  import os
  import torch
  import sys
  import numpy
  import numpy.testing
  from torch_geometric.data import Data
  from torch_points3d.core.data_transform import SaveOriginalPosId
  from torch_points3d.metrics.segmentation_tracker import SegmentationTracker
  from torch_points3d.metrics.segmentation_helpers import SegmentationVoter
  from torch_points3d.metrics.classification_tracker import ClassificationTracker
  from torch_points3d.metrics.s3dis_tracker import S3DISTracker
label_desc: Use image node_id 2 for calling the MockDataset obj's underlying member method code with example usage: obj.test_data() and returns: Data