Status: IN
A single event can match multiple events on the opposite side; the matched flag is set on all participants, so none produce outer-join misses
Source: entries/2026/05/29/stream-join-processor-stream_join_processor.md
for buffered in opposite_buffer[key]:
if self._window.contains(event.timestamp, buffered.event.timestamp):
result = JoinResult(key, left_event, right_event, ...)
results.append(result) # one event matches many