How to tag friends in a wall post using facebbok sdk in android?

How to tag friends in a wall post using facebbok sdk in android?

I am trying to tag one friend in my wall post. But this 'tags' parameter
isn't working. How can i tag one/more friends? Pls help me. Thank you in
advance.
Bundle params = new Bundle();
params.putString("tags", tagged_friends_id);
WebDialog feedDialog = (new WebDialog.FeedDialogBuilder(this,
Session.getActiveSession(),params))
.setOnCompleteListener(new OnCompleteListener() {
@Override
public void onComplete(Bundle values,
FacebookException error) {
if (error == null) {
final String postId =
values.getString("post_id");
if (postId != null) {
Toast.makeText(MainActivity.this,"Posted
story, id: "+postId,
Toast.LENGTH_SHORT).show();
}
else {
// User clicked the Cancel button
Toast.makeText(MainActivity.this,
"Publish cancelled",
Toast.LENGTH_SHORT).show();
}
}
else if (error instanceof
FacebookOperationCanceledException) {
// User clicked the "x" button
Toast.makeText(MainActivity.this,
"Publish cancelled",
Toast.LENGTH_SHORT).show();
}
else {
// Generic, ex: network error
Toast.makeText(MainActivity.this, "Error
posting story",
Toast.LENGTH_SHORT).show();
}
}
}).build();
feedDialog.show();