html_comment.go
func newHTMLComment(ln *line, rslt *result, src *source, parent element, opts *Options) *htmlComment {
	return &htmlComment{
		elementBase: newElementBase(ln, rslt, src, parent, opts),
	}
}
func newHTMLComment(ln *line, rslt *result, src *source, parent element, opts *Options) *htmlComment {
	return &htmlComment{
		elementBase: newElementBase(ln, rslt, src, parent, opts),
	}
}
// newHTMLComment creates and returns an HTML comment.