code: def test_correct_parameters_multi_channels(
      self, boundaries, frequencies, fraction
  ):
      self.assertIsInstance(
          SignalRandAddSquarePulsePartial(
              boundaries, frequencies, fraction
          ),
          SignalRandAddSquarePulsePartial,
      )
      sig = np.load(TEST_SIGNAL)
      partialsquare = SignalRandAddSquarePulsePartial(
          boundaries, frequencies, fraction
      )
      partialsquaresignal = partialsquare(sig)
      self.assertEqual(partialsquaresignal.shape[1], sig.shape[1])
  
file_path: MONAI/tests/test_signal_rand_add_squarepulse_partial.py
imports: from __future__ import annotations
  import os
  import unittest
  from unittest import skipUnless
  import numpy
  from parameterized import parameterized
  from monai.transforms import SignalRandAddSquarePulsePartial
  from monai.utils import optional_import
  from monai.utils.type_conversion import convert_to_tensor
  from tests.utils import SkipIfBeforePyTorchVersion
label_desc: Use image node_id 1 for calling the TestSignalRandAddSquarePulsePartialNumpy obj's underlying member method code with example usage: obj.test_correct_parameters_multi_channels(boundaries, frequencies, fraction) without return types