I don't know if my question makes sense, so I'll try to explain it better.
I'm fairly new to Android, so I'm trying to make an app, and I'm using playing around with the CollapsibleToolBar, and NestedScrollView. It seems that on the newest API there are issues with the NestedScrollView not properly handling flings correctly (how/why are beyond the scope of this question)
I've looked into this, and it seems that someone has a fix for this https://github.com/Dimezis/FlingableNestedScrollView/
They recommend using it on API 21 + though. as it won't properly work as a nested scrolling child for below API 21.
So my question: Can I use this FlingableNestedScrollView only when someone who's using this app is API level 21+, while anyone below, use the Support library's NestedScrollView? Is this easily achievable?