code: def pytorch_resnet18(tmpdir_factory):
      try:
          import torch
          import torchvision.models as models
      except ImportError:
          # Not all environments provide Pytorch, so skip if that's the case.
          return ""
      model = models.resnet18()
      model_file_name = "{}/{}".format(
          tmpdir_factory.mktemp("data"), "resnet18.pth"
      )
      # Trace model into torchscript.
      traced_cpu = torch.jit.trace(model, torch.randn(1, 3, 224, 224))
      torch.jit.save(traced_cpu, model_file_name)
  
      return model_file_name
  
imports: import os
  import pytest
  import tarfile
  import textwrap
  import numpy
  from PIL import Image
  import tvm
  from tvm import relay
  from tvm.driver import tvmc
  from tvm.contrib.download import download_testdata
label_desc: Use image node_id 6 for calling a global function with example usage: pytorch_resnet18(tmpdir_factory) and returns: model_file_name, str