Difference returns the elements in `a` that aren't in `b`.

Returns a unique (ish) id we can attach to resources and tfstate files so they don't conflict with each other Uses base 62 to generate a 6 character string that's unlikely to collide with the handful of tests we run in parallel.

FirstSeenTagKey A tag used to set custom AWS Tags to resources that do not support `created at` timestamp> - EIP & ECS Clusters.