- Multimap<P, DataChangeListenerRegistration<P, D, DCL>> listeners = HashMultimap.create();\r
- Multimap<P, DataCommitHandlerRegistrationImpl<P, D>> commitHandlers = HashMultimap.create();\r
+ Multimap<P, DataChangeListenerRegistration<P, D, DCL>> listeners = Multimaps.synchronizedSetMultimap(HashMultimap.create());\r
+ Multimap<P, DataCommitHandlerRegistrationImpl<P, D>> commitHandlers = Multimaps.synchronizedSetMultimap(HashMultimap.create());\r