class_docstr: Pitch extraction test.
code: def test_spectrum(self):
      wav_path = str(Path(PACKAGE_OPS_DIR).joinpath("data/sm1_cln.wav"))
  
      with self.cached_session(use_gpu=False, force_gpu=False):
          read_wav = ReadWav.params().instantiate()
          input_data, sample_rate = read_wav(wav_path)
  
          pitch = Pitch.params(
              {"window_length": 0.025, "soft_min_f0": 10.0}
          ).instantiate()
          pitch_test = pitch(input_data, sample_rate)
  
          self.assertEqual(tf.rank(pitch_test).eval(), 2)
  
          output_true = np.array(
              [
                  [0.03881124, 0.3000031, -0.02324523],
                  [0.006756478, 0.3000097, 0.01047742],
                  [0.02455365, 0.3000154, 0.00695902],
                  [0.02453586, 0.3000221, 0.008448198],
                  [0.03455311, 0.3000307, -0.07547269],
                  [0.04293294, 0.3000422, -0.04193667],
              ]
          )
  
file_path: delta/delta/data/frontend/pitch_test.py
imports: import delta.compat
  from pathlib import Path
  from delta.data.frontend.read_wav import ReadWav
  from delta.data.frontend.pitch import Pitch
  import numpy
  from core.ops import PACKAGE_OPS_DIR
label_desc: Use image node_id 1 for calling the PitchTest obj's underlying member method code with example usage: obj.test_spectrum() without return types