OptionalextractReduce the body before hashing/reporting (e.g. one JSON field).
Optionalfetchfetch override (testing).
Optionalinit: RequestInitOptionalinit: RequestInitOptionalheadersOptionalintervalPoll interval. Default 60000.
OptionaltimeoutPer-request timeout. Default 15000.
URL watcher — poll an endpoint, get notified when its content changes.