@Override
public RandomAccessFilter buildRandomAccessOrFilter(String[] vals, Properties prop, boolean isNot)
throws IOException {
if (vals.length > 1) {
return new BitSetFilter(new ValueConverterBitSetBuilder(FacetRangeValueConverter.instance,
vals, isNot), new SimpleDataCacheBuilder(getName(), _indexFieldName));
} else {
RandomAccessFilter filter = buildRandomAccessFilter(vals[0], prop);
if (filter == null) return filter;
if (isNot) {