Add a MustNamespace that panics if the namespace wasn't valid

impl/memory/info.go

Index: impl/memory/info.go
diff --git a/impl/memory/info.go b/impl/memory/info.go
index 811e586c3ebdb459bef06e20e4a2fc0ec32ac9de..6d28d5ab45478255432528ab560d1442b1c8b766 100644
--- a/impl/memory/info.go
+++ b/impl/memory/info.go
@@ -56,6 +56,14 @@ func (gi *giImpl) Namespace(ns string) (ret context.Context, err error) {
 	return context.WithValue(gi.c, giContextKey, &globalInfoData{gi.appid, ns}), nil
 }
 
+func (gi *giImpl) MustNamespace(ns string) context.Context {
+	ret, err := gi.Namespace(ns)
+	if err != nil {
+		panic(err)
+	}
+	return ret
+}
+
 func (gi *giImpl) AppID() string {
 	return gi.appid
 }