code: def setUp(self):
      self.imgs = torch.randn(1, 1, 32, 100)
  
imports: import unittest
  import torch
  from mmocr.models.textrecog.backbones import ShallowCNN
label_desc: Use image node_id 1 for calling the TestShallowCNN obj's underlying member method code with example usage: obj.setUp() without return types