DT1 instances need to maintain a reference to any DT1s they belong to so that when they are disposed of, they can also trigger the DT1s to remove their tiles from the cache. This hasn't come up yet, but it may in the future when Zone instances are created and disposed of and a DT1 leaks.
DT1instances need to maintain a reference to anyDT1sthey belong to so that when they are disposed of, they can also trigger theDT1sto remove their tiles from the cache. This hasn't come up yet, but it may in the future whenZoneinstances are created and disposed of and aDT1leaks.