title: Fetch Facebook ID with PyFacebook, "Session key is required"
body: <p>I'm trying to fetch the logged in user's ID with Facebook + PyFacebook via:</p>
  
  <pre><code>#Establish connection to Facebook via API
  f = Facebook(config['app_conf']['pyfacebook.apikey'],
               config['app_conf']['pyfacebook.secret'])
  
  #Get the current Facebook ID
  facebook_id = f.users.getLoggedInUser()
  </code></pre>
  
  <p>But I keep getting the error:</p>
  
  <pre><code>FacebookError: Error 453: A session key is required for calling this method
  </code></pre>
  
  <p>What am I doing wrong?
  Thanks.</p>