code: def test_correct_parameters_multi_channels(self, boundaries):
      self.assertIsInstance(
          SignalRandAddGaussianNoise(boundaries),
          SignalRandAddGaussianNoise,
      )
      sig = convert_to_tensor(np.load(TEST_SIGNAL))
      gaussian = SignalRandAddGaussianNoise(boundaries)
      gaussiansignal = gaussian(sig)
      self.assertEqual(gaussiansignal.shape[1], sig.shape[1])
  
file_path: MONAI/tests/test_signal_rand_add_gaussiannoise.py
imports: from __future__ import annotations
  import os
  import unittest
  import numpy
  from parameterized import parameterized
  from monai.transforms import SignalRandAddGaussianNoise
  from monai.utils.type_conversion import convert_to_tensor
label_desc: Use image node_id 1 for calling the TestSignalRandAddGaussianNoiseTorch obj's underlying member method code with example usage: obj.test_correct_parameters_multi_channels(boundaries) without return types