https://developer.android.com/reference/androidx/viewpager2/adapter/FragmentStateAdapter.FragmentTransactionCallback
FragmentStateAdapter.FragmentTransactionCallback | API reference | Android Developers
api referenceandroiddevelopers
https://developer.android.com/reference/androidx/viewpager2/adapter/FragmentStateAdapter.FragmentTransactionCallback.OnPostEventListener
FragmentStateAdapter.FragmentTransactionCallback.OnPostEventListener | API reference | Android...
api referenceandroid