* Client-Side Metrics Include
* Wiki: https://tiny.amazon.com/cpso0wg6
* Needs to be included at the top of pages because it tracks latency--
* ue_t0 needs to be as close to body load as possible.
* - ue.tag maps to URLType dimension of OnlineQueryLog in PMET. Because we cannot add
* custome data to other dimensions in PMET through CSM, we are replicating it thrice to
* cover each store, page type, and the intersections of the two.
* - Whitelists are listed in the usage guide:
The first Silver Age appearance of Golden Age Flash and the first mention of an Earth-2 where Golden Age heroes live! Barry Allen appears at the Community Center in Central City to perform for kids, and during one of his amazing tricks is mysteriously transported to Keystone City, a place that he recalls that the original Flash once lived. Prepare for the meeting of the Flash of two worlds!