diff --git a/mercurial/branchmap.py b/mercurial/branchmap.py
--- a/mercurial/branchmap.py
+++ b/mercurial/branchmap.py
@@ -189,8 +189,7 @@
         self._closedverified = True
 
     def _verifybranch(self, branch):
-        """ verify head nodes for the given branch. If branch is None, verify
-        for all the branches """
+        """ verify head nodes for the given branch. """
         if branch not in self._entries or branch in self._verifiedbranches:
             return
         for n in self._entries[branch]: