code: def test_ihfftn(self):
      x = random((30, 20, 10))
      expect = fft.ifftn(x)[:, :, :6]
      assert_array_almost_equal(expect, fft.ihfftn(x))
      assert_array_almost_equal(expect, fft.ihfftn(x, norm="backward"))
      assert_array_almost_equal(
          expect * np.sqrt(30 * 20 * 10), fft.ihfftn(x, norm="ortho")
      )
      assert_array_almost_equal(
          expect * (30 * 20 * 10), fft.ihfftn(x, norm="forward")
      )
  
imports: import queue
  import threading
  import multiprocessing
  import numpy
  import pytest
  from numpy.random import random
  from numpy.testing import assert_array_almost_equal, assert_array_equal, assert_allclose
  from pytest import raises
  import scipy.fft
label_desc: Use image node_id 19 for calling the TestFFT1D obj's underlying member method code with example usage: obj.test_ihfftn() without return types