try {
IEclipsePreferences defaultPreferences = getDefaultPreferences();
IEclipsePreferences instancePreferences = getInstancePreferences();
if (newOptions == null){
instancePreferences.clear();
} else {
Enumeration keys = newOptions.keys();
while (keys.hasMoreElements()){
String key = (String)keys.nextElement();
if (!this.optionNames.contains(key)) continue; // unrecognized option