From 630f73a3a52d87b91f4ad153b32a76a655034e89 Mon Sep 17 00:00:00 2001
From: Nick Coghlan <ncoghlan@gmail.com>
Date: Sat, 26 Jun 2021 16:50:39 +1000
Subject: [PATCH] Add back ContextStack alias

---
 contextlib2.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/contextlib2.py b/contextlib2.py
index b529328..0276849 100644
--- a/contextlib2.py
+++ b/contextlib2.py
@@ -767,3 +767,22 @@ class nullcontext(AbstractContextManager, AbstractAsyncContextManager):
 
     async def __aexit__(self, *excinfo):
         pass
+
+
+# Preserve backwards compatibility
+class ContextStack(ExitStack):
+    """Backwards compatibility alias for ExitStack"""
+
+    def __init__(self):
+        warnings.warn("ContextStack has been renamed to ExitStack",
+                      DeprecationWarning)
+        super(ContextStack, self).__init__()
+
+    def register_exit(self, callback):
+        return self.push(callback)
+
+    def register(self, callback, *args, **kwds):
+        return self.callback(callback, *args, **kwds)
+
+    def preserve(self):
+        return self.pop_all()