minor
defect
In the tl:KnowledgeBase, a refetch is performed before a commit, and this refetch event is merged with the existing local changes.
During the refetch, the tl:UpdateEvent is created, but without the modified tl:KnowledgeItems. These are loaded in bulk after the update event is created. For this to work, the current session revision must first be updated to the refetch revision. However, the event is used here to update the modified KBCaches. These caches assume that the objects are present, which can result in a NullPointerException (as happens in an EPP cache).
Test
TestDBKnowledgeBaseCluster#testRefetchWithLocalKBCacheValue