if(typeToData == null)
typeToData = new HashMap(5);
Iterator<Data> children = dataObj.getChildren();
while(children.hasNext()) {
Data child = children.next();
ArrayList list = (ArrayList)typeToData.get(child.getType());
if (list == null) {
list = new ArrayList(5);
typeToData.put(child.getType(), list);
}
list.add(child);
}