LPS-43061 improve the collection (with @shyangzhou's help)
LPS-43061 SF
LPS-43061 Sort
LPS-43061 Not needed
LPS-43061 I think this is more accurate
LPS-44638 1) Root MPI opens IndexReader from IndexWriter for near-real-time search, SPIs open IndexReader from Directory as they don't have an IndexWriter. 2) Root MPI notices all SPIs recursively to invalidate their IndexSearcher
LPS-44638 Fix test
LPS-44638 SF