code: def test_spectral_helper_psd(self, mode, case):
      freqs = getattr(self, f"freqs_{case}")
      spec, fsp, t = mlab._spectral_helper(
          x=self.y,
          y=self.y,
          NFFT=getattr(self, f"NFFT_{case}"),
          Fs=self.Fs,
          noverlap=getattr(self, f"nover_{case}"),
          pad_to=getattr(self, f"pad_to_{case}"),
          sides=self.sides,
          mode=mode,
      )
  
      assert_allclose(fsp, freqs, atol=1e-06)
      assert_allclose(t, getattr(self, f"t_{case}"), atol=1e-06)
      assert spec.shape[0] == freqs.shape[0]
      assert spec.shape[1] == getattr(self, f"t_{case}").shape[0]
  
imports: from numpy.testing import assert_allclose, assert_almost_equal, assert_array_equal, assert_array_almost_equal_nulp
  import numpy
  import pytest
  from matplotlib import mlab
label_desc: Use image node_id 6 for calling the TestSpectral obj's underlying member method code with example usage: obj.test_spectral_helper_psd(mode, case) without return types