@SuppressLint("NotifyDataSetChanged")
    private void initializeFromOriginalList() {

        this.itemList.clear();
        this.itemToOriginalItemMap.clear();
        int idx = 0;
        for (T item : originalItemList) {
            if (isFiltered(item)) {
                this.itemToOriginalItemMap.put(this.itemList.size(), idx);
                this.itemList.add(item);
            }
            idx++;
        }

        if (notifyOnEvents) {
            this.notifyDataSetChanged();
        }
    }
the debug string is used for debug and test purposes. Changing it may break some Unit-Tests
main/src/main/java/cgeo/geocaching/ui/recyclerview/ManagedListAdapter.java