code: def test_triangle_freqs_zeros(self):
      f = filterbank(9, 1024)
      freq_list = [
          40,
          80,
          200,
          400,
          800,
          1600,
          3200,
          6400,
          12800,
          15000,
          24000,
      ]
      freqs = np.array(freq_list, dtype=float_type)
      f.set_triangle_bands(freqs, 48000)
      assert_equal(f(cvec(1024)), 0)
      self.assertIsInstance(f.get_coeffs(), np.ndarray)
  
imports: import numpy
  from numpy.testing import TestCase, assert_equal, assert_almost_equal
  from _tools import assert_warns
  from aubio import fvec, cvec, filterbank, float_type
label_desc: Use image node_id 3 for calling the aubio_filterbank_mel_test_case obj's underlying member method code with example usage: obj.test_triangle_freqs_zeros() without return types