dagutils: fix docstrings for singleton internalize/externalize

mercurial/dagutil.py

@@ -62,7 +62,7 b' class basedag(object):'
         raise NotImplementedError
 
     def externalize(self, ix):
-        '''return a list of (or set if given a set) of node ids'''
+        '''return a node id'''
         return self._externalize(ix)
 
     def externalizeall(self, ixs):
@@ -73,7 +73,7 b' class basedag(object):'
         return list(ids)
 
     def internalize(self, id):
-        '''return a list of (or set if given a set) of node ixs'''
+        '''return a node ix'''
         return self._internalize(id)
 
     def internalizeall(self, ids, filterunknown=False):