How to use

getInstance

method

in

mage.abilities.dynamicvalue.common.ControllerGotLifeCount

public VoraciousWurm(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{1}{G}");
  this.subtype.add(SubType.WURM);
  this.power = new MageInt(2);
  this.toughness = new MageInt(2);
  // Voracious Wurm enters the battlefield with X +1/+1 counters on it, where X is the amount of life you've gained this turn.
  this.addAbility(new EntersBattlefieldAbility(
          new AddCountersSourceEffect(CounterType.P1P1.createInstance(0), ControllerGotLifeCount.getInstance(), true)),
      new PlayerGainedLifeWatcher());
}

public NightmaresThirst(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.INSTANT}, "{B}");
  // You gain 1 life. Target creature gets -X/-X until end of turn, where X is the amount of life you gained this turn.
  this.getSpellAbility().addEffect(new GainLifeEffect(1));
  DynamicValue xValue = new MultipliedValue(ControllerGotLifeCount.getInstance(), -1);
  this.getSpellAbility().addEffect(new BoostTargetEffect(
      xValue, xValue, Duration.EndOfTurn, true
  ).setText("Target creature gets -X/-X until end of turn, where X is the amount of life you gained this turn."));
  this.getSpellAbility().addTarget(new TargetCreaturePermanent());
  this.getSpellAbility().addWatcher(new PlayerGainedLifeWatcher());
}