code: def add_delta_delta(feat, feat_size, order=2):
      """add delta detla"""
      feat_name = "delta_delta"
      graph = None
      # get session
      if feat_name not in _global_sess:
          graph = tf.Graph()
          # pylint: disable=not-context-manager
          with graph.as_default():
              fbank = tf.placeholder(
                  dtype=tf.float32,
                  shape=[None, feat_size, 1],
                  name="fbank",
              )
              feat_with_delta_delta = speech_ops.delta_delta(
                  fbank, order=order
              )
              feat_with_delta_delta = tf.identity(
                  feat_with_delta_delta, name=feat_name
              )
  
      sess = _get_session(feat_name, graph)
      feat = sess.run(
          _get_out_tensor_name(feat_name, 0),
          feed_dict={"fbank:0": feat},
      )
      return feat
  
file_path: delta/delta/data/feat/speech_feature.py
imports: import os
  import numpy
  import delta.compat
  from absl import logging
  from delta.data.feat import speech_ops
  from core.ops import py_x_ops
  from delta.data.feat import python_speech_features
label_desc: Use image node_id 5 for calling a global function with example usage: add_delta_delta(feat, feat_size, order) and returns: feat