/**
* Comparator Interface (based on toString value)
*
* @param o1 Object 1
* @param o2 Object 2
* @return compareTo value
*/
public final int compare(NamePair o1, NamePair o2) {
String s1 = o1 == null ? "" : o1.toString();
String s2 = o2 == null ? "" : o2.toString();
return s1.compareTo(s2); // sort order ??
} // compare
