class_docstr: pvoc object test case 
class_docstr_tok: ["pvoc","object","test","case"]
docstr: check the resynthesis of zeros gives zeros 
docstr_tok: ["check","the","resynthesis","of","zeros","gives","zeros"]
code: def test_zeros(self):
      """check the resynthesis of zeros gives zeros"""
      win_s, hop_s = 1024, 256
      f = pvoc(win_s, hop_s)
      t = fvec(hop_s)
      for _ in range(int(4 * win_s / hop_s)):
          s = f(t)
          r = f.rdo(s)
          assert_equal(t, 0.0)
          assert_equal(s.norm, 0.0)
          try:
              assert_equal(s.phas, 0)
          except AssertionError:
              assert_equal(s.phas[s.phas > 0], +np.pi)
              assert_equal(s.phas[s.phas < 0], -np.pi)
              assert_equal(np.abs(s.phas[np.abs(s.phas) != np.pi]), 0)
              skipTest(
                  "pvoc(fvec(%d)).phas != +0, " % win_s
                  + "This is expected when using fftw3 on powerpc."
              )
          assert_equal(r, 0.0)
  
imports: from numpy.testing import TestCase, assert_equal, assert_array_less
  from _tools import parametrize, skipTest
  from aubio import fvec, cvec, pvoc, float_type
  import numpy
label_desc: Use image node_id 4 for calling the Test_aubio_pvoc_test_case obj's underlying member method code with example usage: obj.test_zeros() without return types