subscribe-options

Including the basic AMPS library:

import com.crankuptheamps.client.*;
import com.crankuptheamps.client.exception.*;

Constructing the command:

Command cmd = new Command(Message.Command.Subscribe)
                   .setTopic(topic)
                   .setOptions(Message.Options.Timestamp)
                   ;

The command can now be used in execute or executeAsync.