public void connect(
@OptionArgument("host") String host,
@OptionArgument("username") String username,
@OptionArgument("password") String password) {
JobHub hub = jobHub;
if (hub == null) {
System.err.println("Hub not running.");
}
if (host.equals("")) {
host = "localhost";
}
if (username.equals("")) {
username = "guest";
}
System.out.printf("Connecting hub to %s\n", host);
hub.connect(host, username, password);
}