public static function setRunMode( $runMode )
    {
        if ( !in_array( $runMode, array( ezcBase::MODE_PRODUCTION, ezcBase::MODE_DEVELOPMENT ) ) )
        {
            throw new ezcBaseValueException( 'runMode', $runMode, 'ezcBase::MODE_PRODUCTION or ezcBase::MODE_DEVELOPMENT' );
        }

        self::$runMode = $runMode;
    }