public void send(RosterEntry rosterEntry, String targetUserID) {
// Create a new message to send the roster
Message msg = new Message(targetUserID);
// Create a RosterExchange Package and add it to the message
RosterExchange rosterExchange = new RosterExchange();
rosterExchange.addRosterEntry(rosterEntry);
msg.addExtension(rosterExchange);
// Send the message that contains the roster
con.sendPacket(msg);
}