code: func installCacheCronHandlerImpl(r *router.Router, base router.MiddlewareChain, be backend.B) {
  	base = base.Extend(func(c *router.Context, next router.Handler) {
  		// Install our Backend into our Context.
  		c.Context = installConfigBackend(c.Context, mustFetchCachedSettings(c.Context), be, cacheConfig{
  			// Use memcache to buffer raw service requests.
  			GlobalCache: func(c context.Context, be backend.B, s *Settings) backend.B {
  				return memcache.Backend(be, s.CacheExpiration())
  			},
  
  			// For cron, do not install the datastore cache Backend. Instead,
  			// install a lasting Handler into the Context to be used for cache
  			// resolution. This is necessary since resolution calls will not be
  			// the result of an actual resolution command (e.g., cache.Get).
  			With: func(c context.Context, be backend.B, s *Settings) context.Context {
  				dsc := datastoreCacheConfig(s)
  				if dsc != nil {
  					c = dsc.WithHandler(c, datastore.CronLoader(be), datastore.RPCDeadline)
  				}
  				return c
  			},
  		})
  		next(c)
  	})
  
  	datastore.Cache.InstallCronRoute("/admin/config/cache/manager", r, base)
  }
docs: // Install our cache cron handler into the supplied Router.
  //
  // bf is a generator function used to get the primary (service) Backend to build
  // on top of. If nil, the "production" (one used by Use) Backend will be used.