class_docstr: test speech feat ops
class_docstr_tok: ["test","speech","feat","ops"]
docstr: test read wav op 
docstr_tok: ["test","read","wav","op"]
code: def test_read_wav(self):
      """test read wav op"""
      with self.cached_session(use_gpu=False, force_gpu=False):
          wavfile = tf.constant(self.wavpath)
          # read wav
          audio, sample_rate = tffeat.read_wav(wavfile, self.hp)
          self.assertEqual(sample_rate.eval(), self.sr_true)
  
          self.assertEqual(audio.eval().shape, (1000, 1))
          self.assertAllEqual(
              audio.eval()[:, 0], self.audio_true[:1000]
          )
  
file_path: delta/delta/data/feat/speech_ops_test.py
imports: import os
  from pathlib import Path
  import numpy
  import delta.compat
  from absl import logging
  from delta.data.feat.speech_feature import load_wav
  from delta.data.feat import speech_ops
  from delta import PACKAGE_ROOT_DIR
label_desc: Use image node_id 2 for calling the SpeechOpsFeatTest obj's underlying member method code with example usage: obj.test_read_wav() without return types