magarena/release/Magarena/scripts/Lab_Rats.groovy

[
    new MagicSpellCardEvent() {
        @Override
        public MagicEvent getEvent(final MagicCardOnStack cardOnStack,final MagicPayedCost payedCost) {
            return new MagicEvent(
                cardOnStack,
                this,
                "PN puts a 1/1 black Rat creature token onto the battlefield. " +
                "If the buyback cost was payed, return SN to its owner's hand as it resolves."
            );
        }

        @Override
        public void executeEvent(final MagicGame game, final MagicEvent event) {
            game.doAction(new MagicPlayTokenAction(
                event.getPlayer(),
                TokenCardDefinitions.get("1/1 black Rat creature token")
            ));
            if (event.isBuyback()) {
                game.doAction(new MagicChangeCardDestinationAction(event.getCardOnStack(), MagicLocationType.OwnersHand));
            }
        }
    }
]