oauth.vim - failed

gistfile1.vim

let s:consumer_key    = 'consumer key'
let s:consumer_secret = 'consumer secret'

let s:access_token = 'access token'
let s:access_token_secret = 'access token secret'

let s:ctx = {
      \ 'consumer_key'        : s:consumer_key ,
      \ 'consumer_secret'     : s:consumer_secret ,
      \ 'access_token'        : s:access_token ,
      \ 'access_token_secret' : s:access_token_secret ,
      \ }

echo oauth#get('https://api.twitter.com/1/statuses/home_timeline.xml', s:ctx, {}, {'per_page' : 50})


" {'header': ['HTTP/1.1 401 Unauthorized', 'Date: Fri, 04 Nov 2011 13:41:28 GMT', 'Status: 401 Unauthorized', 'WWW-Authenticate: OAuth realm="https://api.twitter.com"', 'X-Runtime: 0.38868', 'Content-Type: application/xml; charset=utf-8', 'Content-Length: 169', 'Cache-Control: no-cache, max-age=1800', 'Set-Cookie: k=10.35.55.137.1320414087676387; path=/; expires=Fri, 11-Nov-11 13:41:27 GMT; domain=.twitter.com', 'Set-Cookie: guest_id=v1%3A132041408768056612; domain=.twitter.com; path=/; expires=Mon, 04-Nov-2013 01:41:27 GMT', 'Set-Cookie: _twitter_sess=BAh7CDoPY3JlYXRlZF9hdGwrCIIL0G4zAToHaWQiJTUwMGI2NzEzN2M3MTg0%250AZWJiODkyOTc4YzIwMjUyODM2IgpmbGFzaElDOidBY3Rpb25Db250cm9sbGVy%250AOjpGbGFzaDo6Rmxhc2hIYXNoewAGOgpAdXNlZHsA--db968d45eb9b3e48fdab1d8c69467b9aaf126c90; domain=.twitter.com; path=/; HttpOnly', 'Expires: Fri, 04 Nov 2011 14:11:27 GMT', 'Vary: Accept-Encoding', 'Server: tfe'], 'content': '<?xml version="1.0" encoding="UTF-8"?>
"<hash>
"  <error>Could not authenticate with OAuth.</error>
"  <request>/1/statuses/home_timeline.xml?per_page=50</request>
"</hash>
'}