Function duration_component 

pub fn duration_component(dur: &DurationValue, name: &str) -> Option<i64>

A duration component accessor (d.years, d.monthsOfQuarter, d.secondsOfMinute, d.nanosecondsOfSecond, …) over a typed duration. The *Of* forms give the component within the next-larger unit; the plain forms give the total in that unit (truncated toward zero). None for an unknown name. (#920)