try {
ListData hierItem = (ListData) context
.get(DashHierarchy.DATA_REPOSITORY_NAME);
DashHierarchy hier = (DashHierarchy) hierItem.get(0);
PropertyKey key = hier.findExistingKey(prefix);
if (key == null) return null;
ListData result = new ListData();
for (int i = 0; i < hier.getNumChildren(key); i++) {
PropertyKey child = hier.getChildKey(key, i);