a(...) {
    attributes["download"] = "..."
}

if (tag.attributes.isNotEmpty()) {
    tag.attributesEntries.forEachIndexed { _, e ->
        if (!e.key.isValidXmlAttributeName()) {
            throw IllegalArgumentException("Tag ${tag.tagName} has invalid attribute name ${e.key}")
        }

        out.append(' ')
        out.append(e.key)
        out.append("=\"")
        out.escapeAppend(e.value)
        out.append('\"')
    }
}