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

impl/prod/info.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package prod
 
 import (
         "time"
 
         "github.com/luci/gae/service/info"
@@ skipping 59 matching lines @@
 func (g giImpl) Namespace(namespace string) (context.Context, error) {
         aeCtx, err := appengine.Namespace(g.aeCtx, namespace)
         if err != nil {
                 return g.usrCtx, err
         }
         usrCtx := context.WithValue(g.usrCtx, prodContextKey, aeCtx)
         pc := *getProbeCache(usrCtx)
         pc.namespace = namespace
         return withProbeCache(usrCtx, &pc), nil
 }
+func (g giImpl) MustNamespace(ns string) context.Context {
+        ret, err := g.Namespace(ns)
+        if err != nil {
+                panic(err)
+        }
+        return ret
+}
 func (g giImpl) PublicCertificates() ([]info.Certificate, error) {
         certs, err := appengine.PublicCertificates(g.aeCtx)
         if err != nil {
                 return nil, err
         }
         ret := make([]info.Certificate, len(certs))
         for i, c := range certs {
                 ret[i] = info.Certificate(c)
         }
         return ret, nil
@@ skipping 30 matching lines @@
 func getProbeCache(c context.Context) *infoProbeCache {
         if pc, ok := c.Value(probeCacheKey).(*infoProbeCache); ok {
                 return pc
         }
         return nil
 }
 
 func withProbeCache(c context.Context, pc *infoProbeCache) context.Context {
         return context.WithValue(c, probeCacheKey, pc)
 }