[keycloak-dev] Concurrency & EventsListener SPI

Hi, I am writing a provider for eventsListener SPI. Could anyone tell me if the provider and its provider factory need to be thread safe ? With more details, I need to store some events. To do so, I am using a collection created by the factory and a reference to this collection is passed to the constructor to update it. Does my collection needs to be concurrency-safe or is it not needed? Best regards, Romain