if (src.isEmpty()) {
            return tgt;
        }

        MergingList<T> list;
        if (tgt instanceof MergingList) {
            list = (MergingList<T>) tgt;
        } else {
            list = new MergingList<>(computer, src.size() + tgt.size());
            list.mergeAll(tgt, (t, s) -> s);
        }

        list.mergeAll(src, remapping);