title: How to retrieve last global_step after saver.restore
body: <p>We can save a check point</p>
  
  <pre><code>saver = tf.train.Saver()
  saver.save(sess, FLAGS.train_dir, global_step=step)
  </code></pre>
  
  <p>Then, later, I can restore all variables:</p>
  
  <pre><code>saver.restore(sess, FLAGS.train_dir)
  </code></pre>
  
  <p>I want to get the 'golbal_step' I passed when I call 'saver.save' so that I can continue the training based on the last global_step.</p>
  
  <p>Is there any way to get it? It seems CheckpointState does not include the information. </p>
  
  <pre><code>message CheckpointState {
    // Path to the most-recent model checkpoint.
    string model_checkpoint_path = 1;
  
    // Paths to all not-yet-deleted model checkpoints, sorted from oldest to
    // newest.
    // Note that the value of model_checkpoint_path should be the last item in
    // this list.
    repeated string all_model_checkpoint_paths = 2;
  }
  </code></pre>
  
  <p>Like <a href="https://stackoverflow.com/questions/36113090">Tensorflow get the global_step when restoring checkpoints</a>, I can introduce a new TF variable, but it would be best if I can do it without adding a new variable.Is there any way? </p>