From 9f35bbbfac7f35f681df5b7d226acf285cd4ab78 Mon Sep 17 00:00:00 2001
From: Tim Beyer <35711942+TimFelixBeyer@users.noreply.github.com>
Date: Thu, 13 Jul 2023 23:56:39 +0200
Subject: [PATCH] fix flake

---
 music21/base.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/music21/base.py b/music21/base.py
index a88ffa718..f58f7f7af 100644
--- a/music21/base.py
+++ b/music21/base.py
@@ -1256,7 +1256,7 @@ def purgeOrphans(self, excludeStorageStreams=True) -> None:
             # of the site does not actually have this Music21Object in
             # its elements list, it is an orphan and should be removed
             # note: this permits non-site context Streams to continue
-            if s.isStream and not self in s:
+            if s.isStream and self not in s:
                 if excludeStorageStreams:
                     # only get those that are not Storage Streams
                     if ('SpannerStorage' not in s.classes