* 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:
George and Harold have created the greatest superhero in the history of their elementary school -- and now they're going to bring him to life! Meet Captain Underpants! His true identity is SO secret, even HE doesn't know who he is!