For issue report only

This repo is a demo for a bug issue in facebook/react-native#15051.

Issues

After building and running the React-Native app on iOS or Android from this repo, you'll find some issues:

1. The page is not fully loaded at the very beginning. It only renders some parts of rows, and it takes time to fully load those cells.
2. The renderItem callback in <SectionList/> will be called multiple time for the same cells/rows.
3. When you scroll the <SectionList/> on Android devices, it only update a few cells at a time. That's not smooth as on an iOS App and the UX is bad.