@Override public void attachToSubparser(final Subparser subparser) { subparser.addArgument("number") .help("Specify the phone number, for which to set the trust.") .required(true); MutuallyExclusiveGroup mutTrust = subparser.addMutuallyExclusiveGroup(); mutTrust.addArgument("-a", "--trust-all-known-keys") .help("Trust all known keys of this user, only use this for testing.") .action(Arguments.storeTrue()); mutTrust.addArgument("-v", "--verified-fingerprint") .help("Specify the fingerprint of the key, only use this option if you have verified the fingerprint."); }