/// Return a new `Clock` instance that uses the current execution context's
/// source of time.
Return a new `Clock` instance that uses the current execution context's
source of time.
Return a new ` Clock ` instance that uses the current execution context ' s source of time .
pub fn new() -> Clock {
        CLOCK.with(|current| match current.borrow().as_ref() {
            Some(c) => c.clone(),
            None => Clock::system(),
        })
    }
pub fn new ( ) -> Clock { CLOCK . with ( | current | match current . borrow ( ) . as_ref ( ) { Some ( c ) => c . clone ( ) , None => Clock :: system ( ) , } ) }
Return a new `Clock` instance that uses the current execution context's
source of time.
Return a new ` Clock ` instance that uses the current execution context ' s source of time .