title: Detect when a new page is loaded
body: <p>I'm developing a tool that will browse a site doing a series of actions (clicks, filling forms) and record all the HTTP petitions to verify implementation error/changes </p>
  
  <p>I'm using: </p>
  
  <ul>
  <li>Python 3.6 </li>
  <li>Selenium</li>
  <li>Browsermob proxy</li>
  </ul>
  
  <p>The tool does exactly what I want, it records all the petitions into a single HAR file, my problem is that I can not know which petitions are from what page. What I would like to have is a listener that when a new page is loading start a new HAR page and thus have my information segmented. </p>
  
  <p>Thanks a lot for your help</p>