RTEditor/src/main/java/com/onegravity/rteditor/converter/tagsoup/HTMLWriter.java
private void forceNSDecls() {
        Enumeration<String> prefixes = forcedDeclTable.keys();
        while (prefixes.hasMoreElements()) {
            String prefix = (String) prefixes.nextElement();
            doPrefix(prefix, null, true);
        }
    }
private void forceNSDecls() {
        Enumeration<String> prefixes = forcedDeclTable.keys();
        while (prefixes.hasMoreElements()) {
            String prefix = (String) prefixes.nextElement();
            doPrefix(prefix, null, true);
        }
    }
Force all Namespaces to be declared.
<p>
This method is used on the root element to ensure that the predeclared
Namespaces all appear.