Jyxo\Mail\Parser::getRawHeaders PHP Method

    private function getRawHeaders(string $pid = null) : string
    {
        if (null === $pid) {
            return imap_fetchheader($this->connection, $this->uid, FT_UID);
        }
        $rawHeaders = imap_fetchbody($this->connection, $this->uid, $pid, FT_UID);
        $headersEnd = false !== strpos($rawHeaders, "\n\n") ? strpos($rawHeaders, "\n\n") : strpos($rawHeaders, "\n\r\n");
        if ($headersEnd === false) {
            return '';
        }
        return substr($rawHeaders, 0, $headersEnd);
    }