class_docstr: This is a base class used to create Pytorch operator benchmark.
  module_name is the name of the operator being benchmarked.
  test_name is the name (it's created by concatenating all the
  inputs) of a specific test
code: def _set_backward_test(self, is_backward):
      self._is_backward = is_backward
  
imports: import json
  import time
  import benchmark_cpp_extension
  import torch
label_desc: Use image node_id 2 for calling the TorchBenchmarkBase obj's underlying member method code with example usage: obj._set_backward_test(is_backward) without return types