code: def tf_session():
      if tf.__version__[0] == "1":
          sess = tf.InteractiveSession()
          return sess
  
file_path: DiCE/tests/test_model_interface/test_keras_tensorflow_model.py
imports: import pytest
  import dice_ml
  from dice_ml.utils import helpers
  from dice_ml.utils.helpers import DataTransfomer
label_desc: Use image node_id 1 for calling a global function with example usage: tf_session() and returns: sess