title: Download file generated after click with splinter
body: <p>I want to download a file from a website with splinter where the file is generated after a click on a button and provided by a random URL. Clicking the button makes the file save dialog of the browser appear.</p>
  
  <p>I can find and click the button with</p>
  
  <pre><code>exportButton = browser.find_by_id("exportButton")
  exportButton.click()
  </code></pre>
  
  <p>But how to save the file with a certain name?</p>
  
  <p>Because the URL is random, never in the source code of the page and the Button is a button that triggers JS and not a link, the methods for file downloading with splinter by sending a request with an URL and deal with the response doesn't work. I can't provide an URL. Clicking the button which sends probably an Ajax request to the server which responds with the file is the only way to get it. I use the Chrome web driver in headless mode.</p>