diff -r 58dff81ffba1 -r 54114bba7c7e mercurial/util.py
--- a/mercurial/util.py	Fri Dec 16 00:54:39 2022 -0500
+++ b/mercurial/util.py	Fri Dec 16 14:15:09 2022 -0500
@@ -3213,10 +3213,7 @@
 
     The passed argument is anything that has a ``.read(N)`` method.
 
-    >>> try:
-    ...     from StringIO import StringIO as BytesIO
-    ... except ImportError:
-    ...     from io import BytesIO
+    >>> from io import BytesIO
     >>> uvarintdecodestream(BytesIO(b'\\x00'))
     0
     >>> uvarintdecodestream(BytesIO(b'\\x01'))