fn timestamp(&self) -> u64 {
        self.duration_since(std::time::UNIX_EPOCH)
            .unwrap_or_default()
            .as_secs()
    }
/// Convert `SystemTime` to timestamp in seconds.
Convert `SystemTime` to timestamp in seconds.
Convert ` SystemTime ` to timestamp in seconds .
fn timestamp(&self) -> u64 {
        self.duration_since(std::time::UNIX_EPOCH)
            .unwrap_or_default()
            .as_secs()
    }
fn timestamp ( & self ) -> u64 { self . duration_since ( std :: time :: UNIX_EPOCH ) . unwrap_or_default ( ) . as_secs ( ) }
Convert `SystemTime` to timestamp in seconds.
Convert ` SystemTime ` to timestamp in seconds .
&self
&self