static SourceNameMapperContainerDialogLogic create(
final Elements elements, final ISourceLookupDirector director,
final PresetFieldValues initialParams) {
final Updater updater = new Updater();
Scope rootScope = updater.rootScope();
final List<ValueSource<String>> warningSources = new ArrayList<ValueSource<String>>(2);
// Represents value entered as prefix.
final ValueSource<String> prefixEditor = new ValueSource<String>() {