code: def test_correct_parameters_multi_channels(self):
      self.assertIsInstance(
          SignalFillEmpty(replacement=0.0), SignalFillEmpty
      )
      sig = np.load(TEST_SIGNAL)
      sig[:, 123] = np.NAN
      fillempty = SignalFillEmpty(replacement=0.0)
      fillemptysignal = fillempty(sig)
      self.assertTrue(not np.isnan(fillemptysignal).any())
  
file_path: MONAI/tests/test_signal_fillempty.py
imports: from __future__ import annotations
  import os
  import unittest
  import numpy
  import torch
  from monai.transforms import SignalFillEmpty
  from monai.utils.type_conversion import convert_to_tensor
  from tests.utils import SkipIfBeforePyTorchVersion
label_desc: Use image node_id 1 for calling the TestSignalFillEmptyNumpy obj's underlying member method code with example usage: obj.test_correct_parameters_multi_channels() without return types