--- a/mercurial/localrepo.py	Sat Feb 06 11:28:03 2010 +0100
+++ b/mercurial/localrepo.py	Sat Feb 06 11:29:23 2010 +0100
@@ -326,6 +326,7 @@
         return partial
 
     def branchmap(self):
+        '''returns a dictionary {branch: [branchheads]}'''
         tip = self.changelog.tip()
         if self._branchcache is not None and self._branchcachetip == tip:
             return self._branchcache