fn start_time_millis(&self) -> Option<u64> {
        self.approximate_host_start_time.map(|time| {
            time.duration_since(std::time::SystemTime::UNIX_EPOCH)
                .expect("host time after the epoch")
                .as_millis() as u64
        })
    }
/// Returns the start timestamp, if any, as milliseconds since the UNIX epoch.
Returns the start timestamp, if any, as milliseconds since the UNIX epoch.
Returns the start timestamp if any as milliseconds since the UNIX epoch .
fn start_time_millis(&self) -> Option<u64> {
        self.approximate_host_start_time.map(|time| {
            time.duration_since(std::time::SystemTime::UNIX_EPOCH)
                .expect("host time after the epoch")
                .as_millis() as u64
        })
    }
fn start_time_millis ( & self ) -> Option < u64 > { self . approximate_host_start_time . map ( | time | { time . duration_since ( std :: time :: SystemTime :: UNIX_EPOCH ) . expect ( " " ) . as_millis ( ) as u64 } ) }
Returns the start timestamp, if any, as milliseconds since the UNIX epoch.
Returns the start timestamp if any as milliseconds since the UNIX epoch .
&self
&self