public static int unmaskBaseViewType(int itemViewTypeMask) {
        return itemViewTypeMask & 0xFF; // base view type (HEADER/ITEM/FOOTER/GHOST_HEADER) is lower 8 bits
    }
@param adapterPosition the adapterPosition of the item in question
@return the custom user type of the item at the adapterPosition
android/modules/module_common/src/main/java/github/tornaco/android/thanos/widget/section/SectioningAdapter.java