private IEnumerable <IItemReferenceEntry> GetMatchingReferences(uint itemId, FourCC requiredReferenceType) { ItemReferenceBox itemReferenceBox = this.metaBox.ItemReferences; if (itemReferenceBox != null) { return(itemReferenceBox.EnumerateMatchingReferences(itemId, requiredReferenceType)); } else { return(Enumerable.Empty <IItemReferenceEntry>()); } }