public override SortedDocValues GetSorted(FieldInfo fieldInfo)
{
var field = FIELDS[fieldInfo.Name];
// SegmentCoreReaders already verifies this field is valid:
Debug.Assert(field != null);
var input = (IndexInput)DATA.Clone();
var scratch = new BytesRef();
return new SortedDocValuesAnonymousInnerClassHelper(this, field, input, scratch);
}