[
    //Whenever a creature you control attacks alone, you may tap target creature.
    new MagicWhenAttacksTrigger() {
        @Override
        public MagicEvent executeTrigger(final MagicGame game,final MagicPermanent permanent,final MagicPermanent creature) {
            return (creature.isFriend(permanent) && 
                    creature.getController().getNrOfAttackers() == 1) ?
                new MagicEvent(
                    permanent,
                    new MagicMayChoice(
                        MagicTargetChoice.NEG_TARGET_CREATURE
                    ),
                    new MagicTapTargetPicker(true,false),
                    this,
                    "PN may\$ tap target creature\$."
                ):
                MagicEvent.NONE;
        }
        @Override
        public void executeEvent(final MagicGame game, final MagicEvent event) {
            if (event.isYes()) {
                event.processTargetPermanent(game,new MagicPermanentAction() {
                    public void doAction(final MagicPermanent creature) {
                        game.doAction(new MagicTapAction(creature,true));
                    }
                });
            }
        }
    }
]