code: def test_stn(self):
      stn = STN(
          in_channels=3,
          resized_image_size=(32, 64),
          output_image_size=(32, 100),
          num_control_points=20,
      )
      image = torch.rand(2, 3, 64, 256)
      transformed_image = stn(image)
      self.assertEqual(transformed_image.shape, (2, 3, 32, 100))
  
imports: from unittest import TestCase
  import torch
  from mmocr.models.textrecog.preprocessors import STN, TPStransform
label_desc: Use image node_id 2 for calling the TestTPS obj's underlying member method code with example usage: obj.test_stn() without return types