@Override
    public void ignorableWhitespace(final char[] ch, final int start, final int length) throws SAXException {
        if (depth > 2) {
            handler.ignorableWhitespace(ch, start, length);
        }
    }
Don't end prefix mappings if we are at the root element. Leave the end
processing method to do this.
stroom-pipeline/src/main/java/stroom/pipeline/record/XMLRecordEmitter.java