code: def tensor_by_collection_name(name):
      tensor_name = tf.get_collection(name)[0].decode("UTF-8")
      return sess.graph.get_tensor_by_name(tensor_name)
  
imports: import argparse
  import json
  import tensorflow
  from tensorflow.examples.tutorials.mnist import input_data
label_desc: Use image node_id 20 for calling a global function with example usage: tensor_by_collection_name(name) and returns: sess