public static function getDifference($alias)
    {
        if (!isset(self::$timers[$alias])) {
            throw new \RuntimeException('Timer has not been started');
        }

        return microtime() - self::$timers[$alias];
    }
public static function getDifference($alias)
    {
        if (!isset(self::$timers[$alias])) {
            throw new \RuntimeException('Timer has not been started');
        }

        return microtime() - self::$timers[$alias];
    }
public static function getDifference ( $ alias ) { if ( ! isset ( self :: $ timers [ $ alias ] ) ) { throw new \ RuntimeException ( 'Timer has not been started' ) ; } return microtime ( ) - self :: $ timers [ $ alias ] ; }
Gets current time passed since start.

@param $alias

@return mixed
@throws \RuntimeException
Gets current time passed since start .