@Override
    public boolean equals(Object object) {
        if (this == object) {
            return true;
        }
        if (object != null && object instanceof User) {
            return username.equals(((User)object).getUsername());
        }
        else {
            return false;
        }
    }
Returns the user's roster. A roster is a list of users that the user wishes to know
if they are online. Rosters are similar to buddy groups in popular IM clients.

@return the user's roster.
xmppserver/src/main/java/org/jivesoftware/openfire/user/User.java