public void notifyAllSectionsDataSetChanged() {
        buildSectionIndex();
        notifyDataSetChanged();
        collapsedSections.clear();
        selectionStateBySection.clear();
    }
Notify that all data in the list is invalid and the entire list should be reloaded.
NOTE: This will clear selection state, and collapsed section state.
Equivalent to RecyclerView.Adapter.notifyDataSetChanged.
Never directly call notifyDataSetChanged.
android/modules/module_common/src/main/java/github/tornaco/android/thanos/widget/section/SectioningAdapter.java