class_docstr: test speech feat ops
class_docstr_tok: ["test","speech","feat","ops"]
docstr: test add delta detlas 
docstr_tok: ["test","add","delta","detlas"]
code: def test_delta_delta(self):
      """test add delta detlas"""
      # pylint: disable=invalid-name
      p = tffeat.speech_params(
          sr=self.sr_true,
          bins=40,
          cmvn=False,
          audio_desired_samples=1000,
          add_delta_deltas=False,
      )
  
      with self.cached_session(use_gpu=False, force_gpu=False):
          wavfile = tf.constant(self.wavpath)
          audio, sample_rate = tffeat.read_wav(wavfile, self.hp)
          del sample_rate
  
          feature = tffeat.compute_mel_filterbank_features(
              audio,
              sample_rate=p.audio_sample_rate,
              preemphasis=p.audio_preemphasis,
              frame_length=p.audio_frame_length,
              frame_step=p.audio_frame_step,
              lower_edge_hertz=p.audio_lower_edge_hertz,
              upper_edge_hertz=p.audio_upper_edge_hertz,
              num_mel_bins=p.audio_num_mel_bins,
              apply_mask=False,
          )
  
          feature = tffeat.delta_delta(feature, order=2)
          self.assertEqual(feature.eval().shape, (11, 40, 3))
  
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 8 for calling the SpeechOpsFeatTest obj's underlying member method code with example usage: obj.test_delta_delta() without return types