OptionaldefinitionEntries this drainer dispatched whose completion lost to another party (a lease-expiry takeover finishing first, or a manual recovery). The handler's side effect ran here too — the at-least-once overlap the EffectHandler contract tells handlers to tolerate.
The drained instance's pinned definition fingerprint — carried so the drain telemetry event can slice per definition. Absent only for instances pinned before content fingerprinting.