code: def test_nonzero(self):
      for p in TEST_NDARRAYS:
          image = p(np.asarray([[4.0, 0.0, 2.0], [0, 2, 4]]))  # std = 1
          factor = np.random.rand()
          std_shifter = StdShiftIntensity(factor=factor, nonzero=True)
          result = std_shifter(image)
          expected = p(
              np.asarray(
                  [
                      [4 + factor, 0, 2 + factor],
                      [0, 2 + factor, 4 + factor],
                  ],
                  dtype=np.float32,
              )
          )
          assert_allclose(
              result, expected, atol=0, rtol=1e-5, type_test=False
          )
  
file_path: MONAI/tests/test_std_shift_intensity.py
imports: from __future__ import annotations
  import unittest
  import numpy
  from monai.transforms import ShiftIntensity, StdShiftIntensity
  from monai.utils import dtype_numpy_to_torch
  from tests.utils import TEST_NDARRAYS, NumpyImageTestCase2D, assert_allclose
label_desc: Use image node_id 3 for calling the TestStdShiftIntensity obj's underlying member method code with example usage: obj.test_nonzero() without return types