code: def test_values_forward(self):
      function = feed_forward_comb_filter
      result = comb_filter(sig_1d, function, [2, 3], [0.5, 0.5])
      self.assertTrue(np.allclose(result[:, 0], res_1d_fw_2))
      self.assertTrue(np.allclose(result[:, 1], res_1d_fw_3))
      result = comb_filter(sig_2d, function, [2, 3], [0.5, 0.5])
      self.assertTrue(np.allclose(result[:, :, 0], res_2d_fw_2))
      self.assertTrue(np.allclose(result[:, :, 1], res_2d_fw_3))
  
imports: from __future__ import absolute_import, division, print_function
  import unittest
  from madmom.audio.comb_filters import *
label_desc: Use image node_id 3 for calling the TestCombFilterFunction obj's underlying member method code with example usage: obj.test_values_forward() without return types