code: def test_nans_class(self, params, input_data, expected_value):
      iou_metric = MeanIoU(**params)
      iou_metric(**input_data)
      result, _ = iou_metric.aggregate()
      np.testing.assert_allclose(
          result.cpu().numpy(), expected_value, atol=1e-4
      )
  
file_path: MONAI/tests/test_compute_meaniou.py
imports: from __future__ import annotations
  import unittest
  import numpy
  import torch
  from parameterized import parameterized
  from monai.metrics import MeanIoU, compute_iou
label_desc: Use image node_id 4 for calling the TestComputeMeanIoU obj's underlying member method code with example usage: obj.test_nans_class(params, input_data, expected_value) without return types