Status: IN
Each `(key, timestamp, origin_node)` triple is applied at most once per node, tracked by the `_seen` set, preventing duplicate application in ring topologies where changes propagate through multiple hops
Source: entries/2026/05/29/multi-leader-replication-multi_leader.md
if key in self._seen and (remote_ts, remote_node) in self._seen[key]:
return None # already applied