public  void handle(Callback[] callbacks) throws IOException, UnsupportedCallbackException 
{
        for (int i = 0; i <  callbacks.length; i++) {
            //When the server side need to authenticate the user
            WSPasswordCallback pwcb = (WSPasswordCallback)callbacks[i];
            if (pwcb.getUsage() == WSPasswordCallback.USERNAME_TOKEN_UNKNOWN) {
                if(pwcb.getIdentifer().equals("alice") && pwcb.getPassword().equals("bobPW")) {
                    return;
                } else {
                    throw new UnsupportedCallbackException(callbacks[i], "check failed");
                }
            }
            //When the client requests for the password to be added in to the 
            //UT element
            pwcb.setPassword("bobPW");
        }
}