message: Typescript typing in index is causing compilation error
diff: @@ -30,6 +30,8 @@ interface Group<TDocument, TKey> {
  }
  export class IndexingGroupResults<TDocument> {
  +
  + public groupBy<TKey>(selector: KeySelector<TDocument, TKey>): TKey extends void ? never : IndexingReduceResults<TDocument, TKey>;
  public groupBy<TKey>(selector: KeySelector<TDocument, TKey>): IndexingReduceResults<TDocument, TKey> {
  return new IndexingReduceResults<TDocument, TKey>(selector);
  }
  