How to use

getId

method

in

mage.abilities.keyword.ChangelingAbility

@Override
public void watch(GameEvent event, Game game) {
  if (event.getType() == EventType.DAMAGED_PLAYER) {
    DamagedPlayerEvent dEvent = (DamagedPlayerEvent) event;
    if (dEvent.isCombatDamage()) {
      Permanent creature = game.getPermanent(dEvent.getSourceId());
      if (creature != null && !allSubtypes.contains(creature.getControllerId())) {
        if (creature.getAbilities().containsKey(ChangelingAbility.getInstance().getId()) || creature.isAllCreatureTypes()) {
          allSubtypes.add(creature.getControllerId());
        } else {
          Set<SubType> subtypes = damagingSubtypes.getOrDefault(creature.getControllerId(), new LinkedHashSet<>());
          subtypes.addAll(creature.getSubtype(game));
          damagingSubtypes.put(creature.getControllerId(), subtypes);
        }
      }
    }
  }
}

boolean changeling = false;
boolean changeling2 = false;
if (creature.getAbilities().containsKey(ChangelingAbility.getInstance().getId()) || creature.isAllCreatureTypes()) {
  changeling = true;
if (creature2.getAbilities().containsKey(ChangelingAbility.getInstance().getId()) || creature2.isAllCreatureTypes()) {
  changeling2 = true;