code: def preprocess(_i):
      return torch.rand((1, 3, 224, 224))
  
file_path: BigDL/python/nano/test/pytorch/tests/inference/test_pipeline.py
imports: import platform
  from unittest import TestCase
  import pytest
  import torch
  from bigdl.nano.pytorch import Pipeline
  from torchvision.models import resnet18
label_desc: Use image node_id 2 for calling a global function with example usage: preprocess(_i) and returns: torch