Prefill friend ids in fb:multi-friend-selector

I am displaying the use a multi-friend-selector element, and it works. But I'd like to be able to preselect some friends when the dialog opens, and I don't know if the API allows that. At least, is not listed on the documentation.

My code

  <fb:request-form 
   action='{{iframe_url}}/reqs' 
   method='POST' 
   content='Sending a request'> 
  <input type='hidden' fb_protected='true' name='friend_id' value='{{facebook_id}}'/> 
      <input type='hidden' fb_protected='true' name='req' value='{{req_type}}'
      <fb:multi-friend-selector 
       actiontext='Select the friends you want to send this request' 
       rows='3' 
       showborder='true' 
       email_invite='false' 
       exclude_ids='{{excluded_friends}}'>
     </fb:multi-friend-selector> 
  </fb:request-form>"

I've tried using the tag开发者_如何学Go prefill_ids, but it doesn't seems to make any effect.

PD: Also, it appears to ignore the the email_invite option.

I'm afraid that it is not possible right now. Only workaround is to use attribute exclude_ids in element fb:multi-friend-selector and leave only friends that you want the user to choose from by excluding all the other friends.