WeakReferenceMap

Stores lists by their listSet. Hold lists based on reference counts which are incremented by addListReference and decremented by deleteListReference. Once a reference count is 0, the list is no longer held in the store. Once a reference count is greater than 0, the list is added to the store.

connection.addInstanceReference(allTodos, {});
connection.instanceStore.get({}) //-> allTodos