code: def test_runtime_mask(self):
      mask_data = np.array([[[0, 0, 0], [0, 1, 0], [0, 0, 0]]])
      img = np.array(
          [
              [[1, 1, 1], [2, 2, 2], [3, 3, 3]],
              [[4, 4, 4], [5, 5, 5], [6, 6, 6]],
          ]
      )
      expected = np.array(
          [
              [[0, 0, 0], [0, 2, 0], [0, 0, 0]],
              [[0, 0, 0], [0, 5, 0], [0, 0, 0]],
          ]
      )
  
      result = MaskIntensity()(img=img, mask_data=mask_data)
      assert_allclose(result, expected, type_test="tensor")
  
file_path: MONAI/tests/test_mask_intensity.py
imports: from __future__ import annotations
  import unittest
  import numpy
  import torch
  from parameterized import parameterized
  from monai.transforms import MaskIntensity
  from tests.utils import TEST_NDARRAYS, assert_allclose
label_desc: Use image node_id 2 for calling the TestMaskIntensity obj's underlying member method code with example usage: obj.test_runtime_mask() without return types