title: Recovering command history in Jupyter Notebook?
body: <p>I have been editing a Jupyter Notebook for the past week, and tried saving it today. While attempting to save it, I got an error, so I refreshed the page and successfully saved it.</p>
  
  <p>However, to my dismay almost all of my command history was lost! I still have access to the variables (the kernel never died), but I don't have access to any of the code.</p>
  
  <p>Is there any way to recover the code? The kernel is still running, but I do not see any checkpoints in my notebook.</p>