title: Selenium - python. how to capture network traffic's response
body: <p>I am using python Django to create a web app. 
  i am using selenium to launch a headless browser(phantomjs) and making some clicks till i reach a particular page. 
  I wish to capture network traffic and get the response of a particular network call. This network call actually holds a html doc as it's response.</p>
  
  <p>Any way to achieve this ?</p>