code: def define_graph(self):
      images, labels = self.load()
      return self.torch_function(
          images if self.device == "cpu" else images.gpu()
      )
  
imports: import numpy
  import nvidia.dali.ops
  import nvidia.dali.plugin.pytorch
  import nvidia.dali.types
  import os
  import torch
  from nvidia.dali.pipeline import Pipeline
  from test_utils import get_dali_extra_path
label_desc: Use image node_id 2 for calling the TorchPythonFunctionPipeline obj's underlying member method code with example usage: obj.define_graph() and returns: self