EcludeClonedItemsCrawler

public class ExcludeClonedItemsCrawler : SitecoreItemCrawler
    {
        protected override bool IsExcludedFromIndex(SitecoreIndexableItem indexable, bool checkLocation = false)
        {
            var obj = (Item)indexable;
            if (obj.IsClone)
            {
                this.Index.Locator.GetInstance<IEvent>().RaiseEvent("indexing:excludedfromindex", (object)this.index.Name, (object)obj.Uri);
                return true;
            }
            return base.IsExcludedFromIndex(indexable, checkLocation);
        }
    }