implement missing method for huge recalculation speed increase
implement missing method for huge recalculation speed increase

hachidorii/JNWCollectionView,danielmartinprieto/JNWCollectionView,jwilling/JNWCollectionView,Deadpikle/JNWCollectionView,kettch/JNWCollectionView,Spark-Xl/JNWCollectionView,regexident/JNWCollectionView,konstantinpavlikhin/JNWCollectionView,chriseidhof/JNWCollectionView