public static function start($name = null)
    {
        if (null === $name) {
            static::$time = -static::getTime();
        } else {
            static::$times[$name] = -static::getTime();
        }
    }
public static function start($name = null)
    {
        if (null === $name) {
            static::$time = -static::getTime();
        } else {
            static::$times[$name] = -static::getTime();
        }
    }
public static function start ( $ name = null ) { if ( null === $ name ) { static :: $ time = - static :: getTime ( ) ; } else { static :: $ times [ $ name ] = - static :: getTime ( ) ; } }
Start time. If name is null, start global timer.

@param  string $name
@return void
Start time . If name is null start global timer .