if (count == list.size()) {
                listOfDeletedPositions.sort(comparator);
                for (int i = 0; i < list.size(); i++) adapterListOfEntitiesVM.remove(list.get(i));
                entities.postValue(ListOfDBItemsActivity.adapterState.DELETE);
            }
----------------------
        Observer<adapterState> observerRV = state -> {
            switch (state) {
                case LOAD:
                    adapterForItemsFromDB.notifyDataSetChanged();
                    break;
                case ADD:
                    adapterForItemsFromDB.notifyItemInserted(mViewModel.getAdapterListOfEntitiesVM().size() - 1);
                    break;
                case UPDATE:
                    adapterForItemsFromDB.notifyItemChanged(mViewModel.getUpdatedItemPosition());
                    break;
                case DELETE:
                    for (int index : mViewModel.getListOfDeletedPositions())
                        adapterForItemsFromDB.notifyItemRemoved(index);
            }
        };