code: public T friends_areFriends(int userId1, int userId2)
      throws FacebookException, IOException {
      return this.callMethod(FacebookMethod.FRIENDS_ARE_FRIENDS,
                             new Pair<String, CharSequence>("uids1", Integer.toString(userId1)),
                             new Pair<String, CharSequence>("uids2", Integer.toString(userId2)));
    }
docs: Retrieves whether two users are friends.
  @param userId1
  @param userId2
  @return T
  @see <a href="http://wiki.developers.facebook.com/index.php/Friends.areFriends">
  Developers Wiki: Friends.areFriends</a>