private function isConditionalComment($comment): bool
    {
        if (\preg_match('/^\[if [^\]]+\]/', $comment)) {
            return true;
        }

        if (\preg_match('/\[endif\]$/', $comment)) {
            return true;
        }

        return false;
    }
private function isConditionalComment($comment): bool
    {
        if (\preg_match('/^\[if [^\]]+\]/', $comment)) {
            return true;
        }

        if (\preg_match('/\[endif\]$/', $comment)) {
            return true;
        }

        return false;
    }
private function isConditionalComment ( $ comment ) : bool { if ( \ preg_match ( '/^\[if [^\]]+\]/' , $ comment ) ) { return true ; } if ( \ preg_match ( '/\[endif\]$/' , $ comment ) ) { return true ; } return false ; }
Check if the current string is an conditional comment.

INFO: since IE >= 10 conditional comment are not working anymore

<!--[if expression]> HTML <![endif]-->
<![if expression]> HTML <![endif]>

@param string $comment

@return bool
Check if the current string is an conditional comment .