anchor.diff:    wf:session(facebook_name, FacebookName),
     wf:session(facebook_link, FacebookLink),
     wf:session(twitter_id, TwitterId),
  -  wf:session(twitter_name, TwitterName).
  +  wf:session(twitter_name, TwitterName),
  +  wf:session(redirect_url, RedirectUrl).
  
positive.code:   facebook_name,
    facebook_link,
    twitter_id,
    twitter_name
  }).
  
  get_state() ->
  
negative.code:     facebook_name = wf:session(facebook_name),
      facebook_link = wf:session(facebook_link),
      twitter_id = wf:session(twitter_id),
      twitter_name = wf:session(twitter_name),
      redirect_url = wf:session(redirect_url)
    }.
  
  set_state(undefined) ->
  