code: def test_transform(self, min_pixels, max_pixels):
      self.transform = CropHeight(
          min_pixels=min_pixels, max_pixels=max_pixels
      )
      results = self.transform(copy.deepcopy(self.data_info))
      self.assertEqual(results["img"].shape[:2], results["img_shape"])
      h_diff = self.data_info["img"].shape[0] - results["img_shape"][0]
      self.assertGreaterEqual(h_diff, min_pixels)
      self.assertLessEqual(h_diff, max_pixels)
  
imports: import copy
  import unittest
  import numpy
  from parameterized import parameterized
  from mmocr.datasets.transforms import CropHeight, ImageContentJitter, PadToWidth, PyramidRescale, RescaleToHeight, ReversePixels, TextRecogGeneralAug
label_desc: Use image node_id 2 for calling the TestCropHeight obj's underlying member method code with example usage: obj.test_transform(min_pixels, max_pixels) without return types