title: Restore trained tensorflow model, edit the value associated with a node, and save it
body: <p>I have trained a model with tensorflow and used batch normalization during training. Batch normalization requires the user to pass a boolean, called <code>is_training</code>, to set whether the model is in training or testing phase.</p>
  
  <p>When the model was trained, <code>is_training</code> was set as a constant as shown below</p>
  
  <pre><code>is_training = tf.constant(True, dtype=tf.bool, name='is_training')
  </code></pre>
  
  <p>I have saved the trained model, the files include checkpoint, .meta file, .index file, and a .data. I'd like to restore the model and run inference using it.
  The model can't be retrained. So, I'd like to restore the existing model, set the value of <code>is_training</code> to <code>False</code> and then save the model back. 
  How can I edit the boolean value associated with that node, and save the model again?</p>