Fix failing test to preserve behaviour

diff --git a/requests/sessions.py b/requests/sessions.py
index 8220036326bd3c66c09ab3579c42b99dd566d5af..0e19a866cbd6247d63a2cf5c0e63034c0551fb42 100644 (file)
--- a/requests/sessions.py
+++ b/requests/sessions.py
@@ -78,12 +78,7 @@ def merge_hooks(request_hooks, session_hooks, dict_class=OrderedDict):
     if request_hooks is None or request_hooks.get('response') == []:
         return session_hooks
 
-    ret = {}
-    for (k, v) in request_hooks.items():
-        if v is not None:
-            ret[k] = set(v).union(session_hooks.get(k, []))
-
-    return ret
+    return merge_setting(request_hooks, session_hooks, dict_class)
 
 
 class SessionRedirectMixin(object):