pub fn from_cron(expr: &str) -> Operator<CronTick>Expand description
from_cron: emit a CronTick when the schedule matches the current minute.
The default clock uses UTC SystemTime; pass FromCronOptions::now for a
domain-local clock or deterministic tests. Each matching minute emits at most
once. Requires a graph-local driver (D111); missing driver reports ERROR on
activation.