diff -r c3eacee01c7e -r 48fd02dac1d4 tests/test-wireproto.py
--- a/tests/test-wireproto.py	Tue Mar 01 17:44:41 2016 -0500
+++ b/tests/test-wireproto.py	Tue Mar 01 18:41:43 2016 -0500
@@ -1,5 +1,7 @@
 from __future__ import absolute_import
 
+import StringIO
+
 from mercurial import wireproto
 
 class proto(object):
@@ -21,6 +23,9 @@
     def _call(self, cmd, **args):
         return wireproto.dispatch(self.serverrepo, proto(args), cmd)
 
+    def _callstream(self, cmd, **args):
+        return StringIO.StringIO(self._call(cmd, **args))
+
     @wireproto.batchable
     def greet(self, name):
         f = wireproto.future()