code: def test_image_scale_intensity_ranged_none(self):
      key = "img"
      scaler = ScaleIntensityRanged(
          keys=key, a_min=20, a_max=108, b_min=None, b_max=None
      )
      for p in TEST_NDARRAYS:
          scaled = scaler({key: p(self.imt)})
          expected = (self.imt - 20) / 88
          assert_allclose(scaled[key], p(expected), type_test="tensor")
  
file_path: MONAI/tests/test_scale_intensity_ranged.py
imports: from __future__ import annotations
  import unittest
  from monai.transforms import ScaleIntensityRanged
  from tests.utils import TEST_NDARRAYS, NumpyImageTestCase2D, assert_allclose
label_desc: Use image node_id 2 for calling the IntensityScaleIntensityRanged obj's underlying member method code with example usage: obj.test_image_scale_intensity_ranged_none() without return types