How to use

setTargetPointer

method

in

mage.abilities.effects.common.continuous.GainControlTargetEffect

  @Override
  public boolean apply(Game game, Ability source) {
    Permanent permanent = game.getPermanent(targetPointer.getFirst(game, source));
    if (super.apply(game, source) && permanent != null) {
      GainControlTargetEffect effect = new GainControlTargetEffect(Duration.EndOfGame);
      effect.setTargetPointer(targetPointer);
      game.addEffect(effect, source);
      return true;
    }
    return false;
  }
}

eff.setTargetPointer(new FixedTarget(target));
game.addEffect(eff, source);