Message11361

So we have two distinct ways we use Guava collections. The first is strictly for caching, and this comes up in the regex implementation (python.sre.* registry keys to control). Code that uses regexes is not impacted by changes to this caching, except for performance.
 
The other is in building mappings between Java and Python, such as Java class to Python type maps. Both kinds (trying to use a different term!) of resources are garbage collectable, but during the *lifetime* of the usage of the resource on either end, Python or Java, we need to maintain this mapping and it cannot be thrown away, at least not without observable behavioral changes to using code. Such changes would impact correctness, not just performance.