code: def test_complex_mul(self, test_x, test_y, res_data):
      result = complex_mul(test_x, test_y)
      assert_allclose(result, res_data, type_test=False)
  
file_path: MONAI/tests/test_complex_utils.py
imports: from __future__ import annotations
  import unittest
  import torch
  from parameterized import parameterized
  from monai.apps.reconstruction.complex_utils import complex_abs, complex_conj, complex_mul, convert_to_tensor_complex
  from monai.utils.type_conversion import convert_data_type
  from tests.utils import TEST_NDARRAYS, assert_allclose
label_desc: Use image node_id 3 for calling the TestMRIUtils obj's underlying member method code with example usage: obj.test_complex_mul(test_x, test_y, res_data) without return types