Parsedown::striAtStart( $string,  $needle )

    protected static function striAtStart($string, $needle)
    {
        $len = strlen($needle);

        if ($len > strlen($string))
        {
            return false;
        }
        else
        {
            return strtolower(substr($string, 0, $len)) === strtolower($needle);
        }
    }