title: Fast.Ai EarlyStoppingCallback does not work
body: <p><a href="https://i.stack.imgur.com/AQ7mP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AQ7mP.png" alt="enter image description here"></a></p>
  
  <pre><code>callbacks = [EarlyStoppingCallback(learn, monitor='error_rate', min_delta=1e-5, patience=5)]
  learn.fit_one_cycle(30, callbacks=callbacks, max_lr=slice(1e-5,1e-3))
  </code></pre>
  
  <p>As you can see, I use patience = 5 and min_delta=1e-5 and monitor='error_rate'</p>
  
  <blockquote>
    <p>My understanding is: patience tells how many epochs it waits if improvement is less than min_delta on the monitored value, in this case it's error_rate.</p>
  </blockquote>
  
  <p>So if my understanding was correct, then it would not stop at Epoch 6.</p>
  
  <p>So is this my understanding wrong or the debug in fast.ai lib ?</p>