@Override
        public int compare(final String o1, final String o2) {
            if (o1.startsWith("xsi:") && o2.startsWith("xsi:")) {
                return o1.compareTo(o2);
            } else if (o1.startsWith("xsi:")) {
                return -1;
            } else if (o2.startsWith("xsi:")) {
                return 1;
            }

            return o1.compareTo(o2);
        }
Test whether the given character is a high surrogate

@param ch The character to test.
@return true if the character is the first character in a surrogate pair
stroom-pipeline/src/main/java/stroom/pipeline/xml/util/XMLWriter.java