code: def test_zero_range(self, class_args, img_shape):
      bias_field = RandBiasField(**class_args)
      img = np.ones(img_shape)
      output = bias_field(img)
      np.testing.assert_allclose(output, np.ones(img_shape), rtol=1e-3)
  
file_path: MONAI/tests/test_rand_bias_field.py
imports: from __future__ import annotations
  import unittest
  import numpy
  import torch
  from parameterized import parameterized
  from monai.transforms import RandBiasField
  from tests.utils import TEST_NDARRAYS
label_desc: Use image node_id 2 for calling the TestRandBiasField obj's underlying member method code with example usage: obj.test_zero_range(class_args, img_shape) without return types