code: def _get_session(feat_name, graph=None):
      global _global_sess
      sess = None
      if feat_name not in _global_sess:
          assert graph is not None
          sess = tf.Session(graph=graph)
          _global_sess[feat_name] = sess
      else:
          sess = _global_sess[feat_name]
      return sess
  
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 1 for calling a global function with example usage: _get_session(feat_name, graph) and returns: sess