code: def test_dtype(self):
      key = "img"
      trans_dtype = np.float32
      for dtype in [int, np.float32, np.float64]:
          image = np.random.rand(2, 2, 2).astype(dtype)
          factor = np.random.rand()
          std_shifter = StdShiftIntensityd(
              keys=[key], factor=factor, dtype=trans_dtype
          )
          result = std_shifter({key: image})
          np.testing.assert_equal(
              result[key].dtype, dtype_numpy_to_torch(trans_dtype)
          )
  
file_path: MONAI/tests/test_std_shift_intensityd.py
imports: from __future__ import annotations
  import unittest
  import numpy
  from monai.transforms import ShiftIntensityd, StdShiftIntensityd
  from monai.utils import dtype_numpy_to_torch
  from tests.utils import NumpyImageTestCase2D
label_desc: Use image node_id 5 for calling the TestStdShiftIntensityd obj's underlying member method code with example usage: obj.test_dtype() without return types