code: def forward(self, x):
      x = self.base_model(x)
      _, topk_id = torch.topk(x[0], 1)
      return topk_id
  
imports: import os
  import unittest
  import onnx_test_common
  import parameterized
  import PIL
  import torch
  import torchvision
  from torch import nn
label_desc: Use image node_id 2 for calling the _TopPredictor obj's underlying member method code with example usage: obj.forward(x) and returns: topk_id