We have a lot of data about how to run pre-clearance. The main thing that the new agreement and legislation does is expand it beyond the air agreement. We figured out over the last 50 years how to do it pretty well, and over the years there have been some modifications to the protection and security arrangements at the airports, but I think the main feature is in expanding into other environments beyond air.
On May 29th, 2017. See this statement in context.