I am using selenium webdriver for Python 2.7:

1. Start a browser: `browser = webdriver.Firefox()`.
2. Go to some URL: `browser.get('http://www.google.com')`.

At this point, how can I send a 'Save Page As' command to the browser?

Note: It is not the web-page source that I am interested in. I would like to save the page using the actual 'Save Page As' Firefox command, which yields different results than saving the web-page source.