--- a/mercurial/patch.py	Wed Nov 13 20:42:13 2019 +0100
+++ b/mercurial/patch.py	Sun Dec 01 18:46:10 2019 -0500
@@ -1570,7 +1570,7 @@
 
 
 class binhunk(object):
-    b'A binary patch file.'
+    """A binary patch file."""
 
     def __init__(self, lr, fname):
         self.text = None