OptionalcountOptionalfromInterval token, e.g. "1m", "5m", "1h", "D".
OptionalnoFetch authoritative history instead of a cached snapshot, when supported.
OptionalsignalCancel this consumer's request. Existing feeds may ignore cancellation.
OptionaltimeoutDeadline in milliseconds, including response-body reading.
Optionalto
Preferred number of bars; a date-range feed may return a different count.