@Override
public SortingBuffer<K, V> make() {
Comparator<UniqueKey<K>> comparator = this.keyComparator != null ? new UniqueKeyComparator<K>(keyComparator) : new ComparableUniqueKeyComparator<K>();
BTreeKeySerializer<UniqueKey<K>> uniqueKeySerializer = new UniqueKeyBTreeSerializer<K>(keySerializer, comparator);
BTreeMapMaker maker = db(useHeap).createTreeMap(name).keySerializer(uniqueKeySerializer)
.valueSerializer(valueSerializer);
if (keepsize) maker = maker.counterEnable();
NavigableMap<UniqueKey<K>, V> buffer = maker.make();
return new CloseableSortingBufferWithDuplicates<K, V>(name, useHeap, buffer);
}