How to use

CyclingDiscardCost

in

mage.abilities.costs.common

  @Override
  public CyclingDiscardCost copy() {
    return new CyclingDiscardCost(this);
  }
}

public CyclingAbility(Cost cost) {
  super(Zone.HAND, new DrawCardSourceControllerEffect(1), cost);
  this.addCost(new CyclingDiscardCost());
  this.cost = cost;
  this.text = "Cycling";
}

public CyclingAbility(Cost cost, FilterCard filter, String text) {
  super(Zone.HAND, new SearchLibraryPutInHandEffect(new TargetCardInLibrary(filter), true, true), cost);
  this.addCost(new CyclingDiscardCost());
  this.cost = cost;
  this.text = text;
}

@Override
public boolean apply(Game game, Ability source, Ability abilityToModify) {
  Player controller = game.getPlayer(abilityToModify.getControllerId());
  if (controller != null) {
    if ((abilityToModify instanceof ActivatedAbility && ((ActivatedAbility) abilityToModify).isCheckPlayableMode()) || controller.chooseUse(Outcome.PlayForFree, "Pay {0} to cycle?", source, game)) {
      abilityToModify.getCosts().clear();
      abilityToModify.getManaCostsToPay().clear();
      abilityToModify.getCosts().add(new CyclingDiscardCost());
    }
    return true;
  }
  return false;
}