--- a/mercurial/namespaces.py	Wed Apr 15 20:10:35 2020 +0200
+++ b/mercurial/namespaces.py	Thu Apr 16 22:30:11 2020 +0900
@@ -83,6 +83,9 @@
     def __iter__(self):
         return self._names.__iter__()
 
+    def get(self, namespace, default=None):
+        return self._names.get(namespace, default)
+
     def items(self):
         return pycompat.iteritems(self._names)