code: def test_meltohz(self):
      assert_equal(meltohz(0, htk=True), 0)
      assert_almost_equal(meltohz(2595, htk=True), 6300.0, decimal=1)
  
imports: from unittest import main
  from numpy.testing import TestCase
  from numpy.testing import assert_equal, assert_almost_equal
  from _tools import assert_warns
  from utils import is32bit
  import numpy
  import aubio
  from aubio import hztomel, meltohz
  from aubio import hztomel_htk, meltohz_htk
label_desc: Use image node_id 1 for calling the aubio_hztomel_htk_test_case obj's underlying member method code with example usage: obj.test_meltohz() without return types