title: Tensorboard, only show latest tfevents
body: <p>Tensboard shows all the events which it finds in the given logdir.</p>
  
  <p>If I ran my training (or whatever) multiple times, I will have multiple tfevents file in the logdir. Tensorboard will show all such variable summaries merged together in a graph which looks strange.</p>
  
  <p><a href="https://i.stack.imgur.com/VSSPe.png" rel="noreferrer"><img src="https://i.stack.imgur.com/VSSPe.png" alt="graph"></a></p>
  
  <p>On stdout, it writes sth like:</p>
  
  <pre><code>WARNING:tensorflow:Found more than one graph event per run. Overwriting the graph with the newest event.
  WARNING:tensorflow:Found more than one "run metadata" event with tag step_0000. Overwriting it with the newest event.
  </code></pre>
  
  <p>How can I make it only show the summaries/events from the latest tfevents file, so that it ignores all older tfevents files?</p>