>Output an XML Doctype using the provided attributes.  Output the
            literal text <code>&lt;!DOCTYPE</code>. The "rootElement" attribute is
            required and must be rendered next.  If the "public" attribute is
            defined, render the literal text <code>PUBLIC</code> then render the
            value of the attribute inside double quotes.  If the "system" attribute
            is defined, render it next, inside double quotes.  Close the doctype
            declaration with the litera