--- a/mercurial/changelog.py	Tue Nov 05 14:07:08 2019 -0800
+++ b/mercurial/changelog.py	Tue Nov 05 14:11:30 2019 -0800
@@ -405,10 +405,6 @@
         self.filteredrevs = frozenset()
         self._copiesstorage = opener.options.get(b'copies-storage')
 
-    def __contains__(self, rev):
-        """filtered version of revlog.__contains__"""
-        return 0 <= rev < len(self) and rev not in self.filteredrevs
-
     def __iter__(self):
         """filtered version of revlog.__iter__"""
         if len(self.filteredrevs) == 0: