private void addChildren(
      final HierarchyManager hm, final Node groupNode, final NodeList childNodes) {
    for (final NodeCursor nc = hm.getChildren(groupNode); nc.ok(); nc.next()) {
      final Node n = nc.node();

      if (hm.isGroupNode(n)) {
        addChildren(hm, n, childNodes);
      } else {
        childNodes.add(n);
      }
    }
  }
Listeners that are notified about changes in the node realizer.
java/zylib/src/main/java/com/google/security/zynamics/zylib/yfileswrap/gui/zygraph/realizers/ZyGroupNodeRealizer.java